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  • Coleoptera  (268)
  • Saccharomyces cerevisiae  (233)
  • 42.55
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  • Springer  (846)
  • 1985-1989  (467)
  • 1980-1984  (379)
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  • 1
    Electronic Resource
    Electronic Resource
    Springer
    Journal of industrial microbiology and biotechnology 4 (1989), S. 49-53 
    ISSN: 1476-5535
    Keywords: l-Phenylacetyl carbinol ; Saccharomyces cerevisiae ; Yeast ; Benzaldehyde ; Biotransformation
    Source: Springer Online Journal Archives 1860-2000
    Topics: Biology , Process Engineering, Biotechnology, Nutrition Technology
    Notes: Summary The rate of production ofl-phenylacetyl carbinol bySaccharomyces cerevisiae in reaction mixtures containing benzaldehyde with sucrose or pyruvate as cosubstrate was investigated in short 1 h incubations. The effect of yeast dose rate, sucrose and benzaldehyde concentration and pH on the rate of reaction was determined. Maximum biotransformation rates were obtained with concentrations of benzaldehyde, sucrose and yeast of 6 g, 40 g and 60 g/l, respectively. Negligible biotransformation rates were observed at a concentration of 8 g/l benzaldehyde. The reaction had a pH optimum of 4.0–4.5. Rates of bioconversion of benzaldehyde and selected substituted aromatic aldehydes using both sucrose and sodium pyruvate as cosubstrate were compared. The rate of aromatic alcohol production was much higher when sucrose was used rather than pyruvate.o-Tolualdehyde and 1-chlorobenzaldehyde were poor substrates for aromatic carbinol formation although the latter produced significant aromatic alcohol in sucrose-containing media. Yields of 2.74 and 3.80 g/l phenylacetyl carbinol were produced from sucrose and pyruvate, respectively, in a 1 h reaction period.
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  • 2
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    Journal of industrial microbiology and biotechnology 4 (1989), S. 81-84 
    ISSN: 1476-5535
    Keywords: Ethanol fermentation ; Wheat starch ; Saccharomyces cerevisiae ; immobilization ; Continuous dynamic immobilized biocatalyst bioreactor ; Biocatalyst bioreactor
    Source: Springer Online Journal Archives 1860-2000
    Topics: Biology , Process Engineering, Biotechnology, Nutrition Technology
    Notes: Summary A simple and efficient method of conversion of wheat starch B to ethanol was investigated. Employing a two-stage enzymatic saccharification process, 95% of the wheat starch was converted to fermentable sugars in 40 h. From 140 g/l total sugars in the feed solution, 63.6 g/l ethanol was produced continuously with a residence time of 3.3 h in a continuous dynamic immobilized biocatalyst bioreactor by immobilized cells ofSaccharomyces cerevisiae. The advantages and the application of this bioreactor to continuous alcoholic fermentation of industrial substrates are presented.
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  • 3
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    European journal of nutrition 22 (1983), S. 205-212 
    ISSN: 1436-6215
    Keywords: Schwermetallwirkung ; Malatdehydrogenase ; Glutamatdehydrogenase ; Glycerinaldehyd-3-phosphatdehydrogenase ; Saccharomyces cerevisiae
    Source: Springer Online Journal Archives 1860-2000
    Topics: Agriculture, Forestry, Horticulture, Fishery, Domestic Science, Nutrition , Medicine
    Description / Table of Contents: Summary The difference between cadmium, zinc, lead, and mercury in regard of their effects on the activity of the enzymes tested is very slight. Concentrations higher than 10−5 M reduce significantly the activity of the enzymes, and concentrations of approximately 10−3 M inhibit it completely. An increase of the activity cannot be detected. The addition of combinations of cadmium, zinc, and lead results in a summing up of the toxic effects, whereas the interaction between mercury and the other three heavy metals shows a cumulative effect, which is appointed nearly completely by the heavy metal more toxic. The findings suggest that under in-vitro conditions there exists a direct interaction between the heavy metals and the enzymes.
    Notes: Zusammenfassung Die vier Schwermetalle Cadmium, Zink, Blei und Quecksilber unterscheiden sich in ihrer Wirkung auf die Aktivität der untersuchten Enzyme nur sehr wenig. Konzentrationen über 10−5 M vermindern die Enzymaktivität signifikant, und Konzentrationen von etwa 10−3 M unterbinden sie völlig. Eine Steigerung der Enzymaktivität läßt sich nicht feststellen. Die Zugabe von Cadmium-, Zink- und Bleikombinationen führt zu einer Addition der toxischen Effekte, während bei der Interaktion zwischen Quecksilber und den anderen drei Schwermetallen die Gesamtwirkung fast ausschließlich durch das stärker hemmende Schwermetall allein bestimmt wird. Die erhaltenen Ergebnisse lassen vermuten, daß es unter Invitro-Bedingungen zu einer direkten Wechselwirkung zwischen den Schwermetallen und den Enzymen kommt.
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  • 4
    ISSN: 1570-7458
    Keywords: Ceutorhynchus constrictus ; Coleoptera ; Curculionidae ; Ceutorhynchinae ; Alliaria petiolata ; garlic mustard ; Brassicaceae ; Cruciferae ; glucosinolates ; sinigrin ; host plant selection ; monophagous ; feeding stimulants
    Source: Springer Online Journal Archives 1860-2000
    Topics: Biology
    Description / Table of Contents: Zusammenfassung Ceutorhynchus constrictus Marsh. (Coleoptera: Chrysomelidae: Ceutorhynchinae) ist ein monophager Rüsselkäfer, der an Knoblauchhederich frisst. Das Wirtswahl-Verhalten dieses Käfers ist im Labor untersucht worden. Die meisten Crucifiren waren im Wahlversuche nicht akzeptiert, wenn Knoblauchhederich als Vergleichspflanze vorhanden war. Von Brassica nigra, Sinapis alba, und Thlaspi arvense wurden im Vergleich gleiche Mengen verzehrt wie von der Wirtspflanze. Blühende Descurainia sophia Pflanzen wurden, im Gegensatz zu Jungpflanzen der gleichen Art, angenommen. Die wichtichsten Phagostimulanten in Extrakten von Knoblauchhederich-Blättern waren ungeladene, wasserlösliche Substanzen. Das häufigste Glukosinolat im Knoblauchhederich, Sinigrin, war auch ein Phagostimulant. Doch war die phagostimulierende Wirkung von Sinigrin nur in Kombinationen mit noch nicht identifizierten, ungeladenen Substanzen aus Knoblauchhederich-Blätter nachweisbar. Wirtspfanzen-Beziehungen von monophagen Insekten werden diskutiert im Zusammenhang mit der Eigenart des Glukosinolat-Inhaltes ihrer Wirtspflanzen.
    Notes: Abstract Host plant relations of the monophagous weevil Ceutorhynchus constrictus Marsh. (Coleoptera: Curculionidae: Ceutorhynchinae) feeding on garlic mustard, Alliaria petiolata (Bieb.) Cavara & Grande (Cruciferae) were studied in the laboratory. Most other crucifers were rejected in choice tests using garlic mustard as a reference plant, but Brassica nigra, Sinapis alba and Thlaspi arvense were as acceptable as the host plant. Flowering plants of Descurainia sophia were acceptable while young plants of this species were not. The most important feeding stimulants in extracts of garlic mustard were uncharged, water soluble compounds. The most abundant glucosinolate in garlic mustard, sinigrin, was a feeding stimulant, too. However, the feeding stimulatory activity of sinigrin was only expressed in the presence of still unidentified uncharged compounds from garlic mustard leaves. Host plant relations in monophagous crucifer-feeding insects is discussed in relation to the distinctness of glucosinolate patterns found in their host plants.
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  • 5
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    Entomologia experimentalis et applicata 37 (1985), S. 241-245 
    ISSN: 1570-7458
    Keywords: Coleoptera ; Bruchidae ; Callosobruchus ; cowpea weevil ; egg recognition ; oviposition deterrents
    Source: Springer Online Journal Archives 1860-2000
    Topics: Biology
    Description / Table of Contents: Résumé Plusieurs expériences ont été réalisées pour déterminer pour quelles raisons les femelles de Callosobruchus maculatus évitent de pondre sur les graines portant des oeufs. La répulsion a été associée à l'oeuf lui-même et non à une autre activité de l'adulte sur la graine. Des stimuli tant chimiques que physiques (tactiles) ont semblé impliqués dans la découverte des oeufs; la substance répulsive était plus soluble dans le méthanol que dans l'éther ou l'eau. Contrairement à des études antérieures sur C. chinensis, nous avons observé que les femelles n'étaient pas dissuadées de pondre sur des graines exposées préalablement à de fortes densités de mâles.
    Notes: Abstract Several experiments were conducted to determine the mechanism by which ovipositing cowpea weevils, Callosobruchus maculatus (F.), avoid egg-laden seeds. Deterrence was associated with the egg itself and not with other adult activities on the host. Both chemical and physical (tactile) stimuli appear to be involved in egg recognition; the chemical deterrent was more soluble in methanol than in ether or water. Contrary to a previous study using C. chinensis (L.), we found that females were not deterred from ovipositing on seeds that had been exposed to high densities of males.
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  • 6
    ISSN: 1570-7458
    Keywords: Pterostichus melanarius ; Coleoptera ; Carabidae ; pitfall traps ; insecticides ; prey ; hunger ; activity ; Rhopalosiphum padi ; Fenitrothion ; Sumicidin (Fenvalerate) ; spring barley
    Source: Springer Online Journal Archives 1860-2000
    Topics: Biology
    Description / Table of Contents: Résumé Au cours d'essais à grande échelle, effectués en 1981 et 1982, sur orge de printemps, pour évaleur l'effet des insecticides Fenitrothion et Sumicidine (fenvalerate) sur les arthropodes utiles, un accroissement significatif des captures, dans des trappes pièges de Barber, de Pterostichus melanarius (Illiger) a été observé plusierus semaines après le traitement dans les lots traités par rapport aux lots témoins. Significativement plus de femelles de P. melanarius ont été capturées dans les parcelles traitées pendant cette période d'accroissement après traitement. Une diminution correspondante dans les populations de proies a été observée à la suite des traitements. Chaque femelle de P. melanarius des parcelles traitées avait une fraction significativement moins importance de son intestin remplie d'aliments solides (arthropodes) que celles des parcelles non traitées. Des auteurs précédents avaient observé des taux de capture plus rapides dans les trappes et ne plus grande mobilité des carabes affamés. La réduction des populations proies par l'application d'insecticides affamerait les carabes dont l'activité serait par suite plus élevée. Comme le taux de captures dans les trappes est dû à la fois à la taille de la population et à son activité, on en déduit que la capture par trappes seule ne peut donner une image exacte de l'effet des insecticides sur les populations de carabes dans les champs.
    Notes: Abstract During large-scale field experiments in 1981 and 1982, designed to assess the effects of the insecticides Fenitrothion and Sumicidin (Fenvalerate) on beneficial arthropods in spring barley, significant increases in pitfall-trap catches of Pterostichus melanarius (Illiger) were observed in treated plots compared to untreated controls, several weeks after treatment. Significantly more female P. melanarius were caught in treated plots during these post-treatment increases. Corresponding decreases were observed in prey populations following treatments. Individual female P. melanarius from treated plots had significantly fewer of their gut areas full of solid (arthropod) food when compared to those from untreated control plots. Earlier workers observed both faster recapture rates in pitfalls and higher mobility in hungry carabid beetles. The following hypothesis is suggested: reducing prey populations by the application of insecticides results in hungrier carabid beetles with consequently higher activity. Since pitfall-trap catch is determined not only by population size but also activity, it is argued that pitfall-trap catches alone cannot give a true measure of the effects of insecticides on carabid populations in the field.
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  • 7
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    Journal of insect behavior 2 (1989), S. 139-141 
    ISSN: 1572-8889
    Keywords: Coleoptera ; Heteroceridae ; egg guarding ; parental care ; predation
    Source: Springer Online Journal Archives 1860-2000
    Topics: Biology
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  • 8
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    Journal of insect behavior 2 (1989), S. 841-847 
    ISSN: 1572-8889
    Keywords: cost of mating ; semelparous ; Photinus collustrans ; Coleoptera ; Lampyridae
    Source: Springer Online Journal Archives 1860-2000
    Topics: Biology
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  • 9
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    Journal of insect behavior 1 (1988), S. 111-115 
    ISSN: 1572-8889
    Keywords: Coleoptera ; Anobiidae ; Anobium punctatum ; sex pheromone ; flying beetles ; wind tunnel ; Stegobium paniceum
    Source: Springer Online Journal Archives 1860-2000
    Topics: Biology
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  • 10
    ISSN: 1572-8773
    Keywords: Manganese ; Electron spin resonance ; Superoxide dismutase ; Saccharomyces cerevisiae ; Yeast
    Source: Springer Online Journal Archives 1860-2000
    Topics: Biology , Chemistry and Pharmacology
    Notes: Summary Manganese accumulation was studied by room-temperature electron spin resonance (ESR) spectroscopy inSaccharomyces cerevisiae grown in the presence of increasing amounts of MnSO4. Mn2+ retention was nearly linear in intact cells for fractions related to both low-molecular-mass and macromolecular complexes (‘free’ and ‘bound’ Mn2+, respectively). A deviation from linearity was observed in cell extracts between the control value and 0.1 mM Mn2+, indicating more efficient accumulation at low Mn2+ concentrations. The difference in slopes between the two straight lines describing Mn2+ retention at concentrations lower and higher than 0.1 mM, respectively, was quite large for the free Mn2+ fraction. Furthermore it was unaffected by subsequent dialyses of the extracts, showing stable retention in the form of low-molecular-mass complexes. In contrast, the slope of the line describing retention of ‘bound’ Mn2+ at concentrations higher than 0.1 mM became less steep after subsequent dialyses of the cell extracts. This result indicates that the macromolecule-bound Mn2+ was essentially associated with particulate structures. In contrast to Cu2+, Mn2+ had no effect on the major enzyme activities involved in oxygen metabolism except for a slight increase of cyanide-resistant Mn-superoxide dismutase activity, due to dialyzable Mn2+ complexes.
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  • 11
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    Entomologia experimentalis et applicata 39 (1985), S. 81-84 
    ISSN: 1570-7458
    Keywords: induced change ; induced resistance ; chemical change ; feeding ; herbivore ; feeding tests ; feeding preferences ; Coleoptera ; Chrysomelidae
    Source: Springer Online Journal Archives 1860-2000
    Topics: Biology
    Description / Table of Contents: Résumé Les choix alimentaires d'un groupe de chrysoméles spécialistes ou généralistes a été étudié en utilisant 3 méthodes: plantes entières, feuilles coupées, rondelles de feuilles. Les méthodes utilisées out eu un effet très significatif sur les préférences relatives des chrysomèles du maïs, du haricot et de la courge. Dans quelques cas le seuil de signification statistique pour un choix particulier a été modifié par la méthode utilisée et dans d'autres cas l'ordre de préférence a été totalement inversé. Les choix alimentaires des spécialistes ont été moins affectés par la méthode utilisée que pour les espèces les plus généralistes. Il y a eu aussi un effet plus important des différences entre les méthodes rondelle de feuilles et feuille entière qu'entre feuille entière et plante entière. Les changements chimiques induits dans les plantes par les dégâts sont probablement très répandus et les chercheurs devraient en tenir compte quand ils programment et interprètent des expériences sur les préférences alimentaires.
    Notes: Abstract Feeding preferences of a group of specialist and generalist chrysomelid beetles were examined using three test methods: whole plants, excised leaves and leaf discs. Method of testing had a very significant effect on relative preferences of the beetles for corn, bean and squash. In some cases the level of statistical significance for a particular preference was affected by test methodology and in other cases the direction of preference was reversed altogether. The feeding preferences of the specialist beetle species were less affected by test method than were the more generalist species. There was also a much greater effect of the difference in test method between the disc test and whole leaf test than between the whole leaf test and whole plant test. Chemical changes in plants induced by damage are probably quite widespread in plants and investigators should take this into account when designing and interpreting tests of insect feeding preference.
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  • 12
    ISSN: 1570-7458
    Keywords: Aggregation pheromone ; sitophilate ; 1-ethylpropyl 2-methyl-3-hydroxypentanoate ; stereoisomers ; enantiomers ; Sitophilus granarius ; granary weevil ; Coleoptera ; Curculionidae
    Source: Springer Online Journal Archives 1860-2000
    Topics: Biology
    Description / Table of Contents: Résumé S. granarius L. est un déprédateur important des grains stockés. Le (R*,S*)-1-éthylpropyl 2-méthyl-3-hydroxypentanoate a été identifié en 1987 comme le principal composé du sitophilate, la phéromone mâle d'agrégation de S. granarius. La composition énantiométrique du sitophilate a été déterminée par 3 méthodes: 1) tests biologiques des énantiomères synthétiques (2S,3R) et (2R,3S) du diastéréomère actif (R*,S*); 2) spectrométrie RMN 1H des esters Mosher dérivés de la phéromone naturelle et des sitophilates de synthèse (2S*,3R*)-et (2R*,3S*); 3) comparaison en capillarité GLC des temps de rétention des dérivés naturels de la phéromone et des 2 éniantiomères de synthèse. La combinaison des 3 méthodes confirme que le (2S,3R) énantiomère est la forme active du sitophilate. Le mâle produit 〉96% de l'énantiomère (2S,3R). Il n'y a pas eu attraction de S. granarius par le (2R,3S) sitophilate. S. oryzae L. et S. zeamais Motsch n'ont pas été attirés par le (2S,3R)-sitophilate. L'utilisation du (2S,3R)-1-éthylpropyl 2-méthyl-3-hydroxypentanoate dans les pièges devrait permettre une détection précoce de la présence de S. granarius dans des stocks de grains.
    Notes: Abstract The enantiomeric composition of sitophilate, the granary weevil [Sitophilus granarius (L.)] male-produced aggregation pheromone [(R*,S*)-1-ethylpropyl 2-methyl-3-hydroxypentanoate)], was determined by three methods: (1) bioassaying the synthetic (2S,3R) and (2R,3S) enantiomers of the active (R*,S*) diastereomer; (2) 1H NMR spectroscopy of Mosher ester derivatives of the natural pheromone and synthetic (2S,3R)-and (2R,3S)-sitophilate; and (3) capillary GLC comparisons of the retention times of derivatized natural pheromone and the two synthetic enantiomers. The combined methods confirmed the (2S,3R) enantiomer as the active form of sitophilate. Male granary weevils were shown to produce 〉96% (2S,3R)-sitophilate. No significant attraction of S. granarius by the (2R,3S) enantiomer was observed. Rice and maize weevils [S. oryzae (L.) and S. zeamais Motschulsky] were not attracted by (2S,3R)-sitophilate.
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  • 13
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    Entomologia experimentalis et applicata 51 (1989), S. 133-140 
    ISSN: 1570-7458
    Keywords: Coleoptera ; Chrysomelidae ; Leptinotarsa decemlineata ; Colorado potato beetle ; Solanaceae ; Solanum berthaultii ; potato ; plant resistance ; glandular trichomes
    Source: Springer Online Journal Archives 1860-2000
    Topics: Biology
    Description / Table of Contents: Résumé Les mécanismes de défense de la pomme de terre sauvage, S. berthaultii Hawkes, aux larves de Leptinotarsa decemlineata Say, ont été étudiés par ablation sélective des trichomes glandulaires et par l'élimination de leur exsudat des folioles, et par comparaison avec S. tuberosum L. qui a perdu les trichomes glandulaires défensifs A et B. L'ablation des trichomes A a augmenté la proportion de larves ayant consommé S. berthaultii. L'élimination de l'exsudat des trichomes B a augmenté la proportion de consommatrices et réduit la mortalité. Les principaux composés actifs de l'exsudat B, c'est-à-dire des esters d'acides gras de sucrose, n'étaient actifs qu'en présence de trichomes A. Les esters de sucrose n'ont pas modifié la consommation larvaire sur folioles de S. tuberosum, ou sur disques de feuilles de S. berthaultii dont les trichomes A avaient été enlevés. La croissance des larves survivantes n'a pas été modifiée significativement par l'ablation des trichomes A ou l'élimination de l'exsudat de B. La croissance des larves a été significativement augmentée quand les folioles de S. berthaultii ont été incorporés dans l'aliment artificiel après élimination de la barrière physique due aux pédoncules B. La croissance a été de même importance sur aliments artificiels contenant des feuilles (fraiches ou en poudre lyophylisée) de S. berthaultii ou de S. tuberosum, mais plus faible que sur folioles de S. tuberosum. La présence de trichomes A est indispensable à la résistance de S. berthaultii aux L, de L. decemlineata. Les gouttelettes de type B contenant des esters de sucrose augmentent l'expression de la résistance en présence d'une défense active par trichomes A.
    Notes: Abstract The defensive mechanisms of the wild potato, solanum berthaultii Hawkes, to larvae of the Colorado potato beetle, Leptinotarsa decemlineata (Say), were studied by selective removal of glandular trichomes and trichome exudates from leaflets, and by comparing performance on S. berthaultii and on the cultivated potato, S. tuberosum L., which lacks defensively active type A and B glandular trichomes. Removal of type A trichomes increased the proportion of larvae that fed on S. berthaultii. Removal of the exudate from type B trichomes increased the proportion of larvae that fed and led to a decrease in mortality. The predominant active compounds in type B exudate, i.e. fatty acid esters of sucrose, were only effective in the presence of type A trichomes. Sucrose esters did not affect larval feeding on S. tuberosum leaflets or on S. berthaultii leaf discs from which the type A trichomes had been removed. Growth of surviving larvae was not significantly affected by removing type A trichomes or type B exudate. Growth of larvae was significantly increased when S. berthaultii leaflets were presented in artificial diet which eliminated the physical barrier of the type B stalks. Growth was no different on artificial diet containing either S. berthaultii or S. tuberosum leaf material (fresh or lyophilized powder) but was poorer on these diets than on S. tuberosum leaflets. The presence of type A trichomes is a fundamental requirement for expression of S. berthaultii resistance to L1 L. decemlineata. Type B droplets containing sucrose esters increase the expression of resistance in the presence of defensively-active type A trichomes.
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  • 14
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    Cellular and molecular life sciences 40 (1984), S. 1159-1161 
    ISSN: 1420-9071
    Keywords: Saccharomyces cerevisiae ; 5-trifluoromethyl-6-àzauracil ; yeast cell cultures ; cell division ; inhibition of
    Source: Springer Online Journal Archives 1860-2000
    Topics: Biology , Medicine
    Notes: Summary Cell division, as studied in asynchronous cultures of yeast cells, is sensitive to 5-trifluoromethyl-6-azauracil (F3CAzU). Under defined conditions (10 mmoles l−1 F3CAzU) this compound blocks immediately and completely the process of cell division. Using synchronized cells, the time-point at which division process of yeast cell can be inhibited by F3CAzU has been determined. The inhibitor effect of this compound is completely reversed by thymine, thymidine and uracil.
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  • 15
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    Cellular and molecular life sciences 43 (1987), S. 886-888 
    ISSN: 1420-9071
    Keywords: Saccharomyces cerevisiae ; trichothecenes ; mycotoxins ; vitamins
    Source: Springer Online Journal Archives 1860-2000
    Topics: Biology , Medicine
    Notes: Summary Several trichothecene mycotoxins were shown to inhibit the growth ofSaccharomyces cerevisiae. This effect was most pronounced with the macrocyclic trichothecenes, especially verrucarin A. Much less growth inhibition was observed with T-2 toxin. Verrucarol, diacetoxyscirpenol, acetyl T-2 toxin, HT-2 toxin, T-2 tetraol and neosolaniol were inactive at a concentration of 75 μg of toxin per disc. Incubation ofS. cerevisiae with verrucarin A together with vitamins resulted in a decrease in toxicity. Pyridoxine-HCl, Ca-pantothenate, thiamine-HCl and α-tocopheryl acetate were amongst the most potent of the vitamins tested which reversed growth inhibition, overcoming the inhibitory potential of the toxins.
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  • 16
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    Cellular and molecular life sciences 43 (1987), S. 888-890 
    ISSN: 1420-9071
    Keywords: Thiaminase ; thiamine ; thiamine antagonist ; Saccharomyces cerevisiae
    Source: Springer Online Journal Archives 1860-2000
    Topics: Biology , Medicine
    Notes: Summary It was found that cell-free extracts ofSaccharomyces cerevisiae contain thiaminase II which hydrolyzes thiamine and thiamine analogs. The possible involvement of this enzyme and thiamine-synthesizing enzymes in thiamine production from thiamine antagonists is discussed.
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  • 17
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    Cellular and molecular life sciences 42 (1986), S. 204-207 
    ISSN: 1420-9071
    Keywords: Coleoptera ; chemical defense ; feeding deterrent ; alkaloid ; homotropane
    Source: Springer Online Journal Archives 1860-2000
    Topics: Biology , Medicine
    Notes: Summary The blood of the Mexican bean beetle (Epilachna varivestis) contains a homotropane alkaloid, euphococcinine (1). The beetles ‘reflex bleed’ when disturbed, thereby deploying the alkaloid, which is provenly deterrent to spiders and ants. Newly emerged adults lack the alkaloid, but the compound builds up to deterrent levels in their blood within days. Eggs and larvae ofEpilachna are devoid of the compound.
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  • 18
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    Entomologia experimentalis et applicata 30 (1981), S. 151-156 
    ISSN: 1570-7458
    Keywords: Xyleborus ferrugineus ; pupae ; ecdysteroids ; pharate adult ; radioimmunoassay ; Coleoptera ; Scolytidae
    Source: Springer Online Journal Archives 1860-2000
    Topics: Biology
    Description / Table of Contents: Zusammenfassung Der Ecdysteroidtiter weiblicher Puppen von Xyleborus ferrugineus (Fabr.) wurde geschätzt, indem ganze Tiere homogenisiert und radioimmunologisch untersucht wurden. Ein ausgeprägtes Maximum an Ecdysteroiden wurde bei 36 Stunden Puppenent-wicklung beobachtet (743 pg/mg Körpergewicht). Der Titer nahm ab auf 299 pg/mg im Pharatstadium und auf 193 pg/mg unmittelbar vor Schlüpfen der Adulten. Qualitative Studien mit HPLC ergaben in frischen Puppen ein Verhältnis von 3:1 Ecdyson zu 20-Hydrooxyecdyson. Pharatstadien enthielten vor allem 20-Hydrooxyecdyson. Das beobachtete einzige Maximum im Titer stimmt überein mit den Resultaten bei andern untersuchten Coleopteren.
    Notes: Abstract Ecdysteroid titers were estimated on the whole body homogenates of Xyleborus ferrugineus (Fabr.) female pupae during development by radioimmunoassay. A distinct peak of ecdysteroids was observed at 36-hr pupal development (743 pg/mg body wt). Titer declined to 299 pg/mg by the pharate adult stage and to 193 pg/mg body wt just before adult emergence. Qualitative studies by HPLC revealed a ratio of 3:1 ecdysone to 20-hydroxyecdysone in the initial pupal stage. Pharate adults had mainly 20-hydroxyecdysone. The observed single peak in ecdysteroid titer agrees with findings in other studied coleopteran species.
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  • 19
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    Entomologia experimentalis et applicata 37 (1985), S. 113-121 
    ISSN: 1570-7458
    Keywords: Hypera postica ; alfalfa weevil ; allozyme analysis ; Coleoptera ; Curculionidae
    Source: Springer Online Journal Archives 1860-2000
    Topics: Biology
    Description / Table of Contents: Résumé Les allozymes d'Hypera de l'est des USA (Beltsville, Maryland; Washington Co., Illinois), de l'ouest des USA (Logan et St Georges, Utah) et ‘égyptiens’ (Yuma, Arizona; Westmorland, Californie) ont été analysés par électrophorèse sur gel d'acrylamide. L'étude a porté sur 22 loci de 12 enzymes (ACPH, ADH, AMY, AO, EST, GOT, G-6PDH, MDH, ME, SOD, TYR, XDH). L'hétérozygotie moyenne de la population était 0.231, avec une moyenne de loci polymorphes de 0.536. La distance génétique moyenne de l'ensemble des populations était de 0.033 et l'indice de fixation de 0.024. Des loci caractéristiques ont été trouvés qui pourraient permettre de distinguer les Hypera occidentaux des orientaux et des ‘égyptiens’. La faible distance génétique entre les Hypera orientaux et ‘égyptiens’ suggère qu'ils appartiennent à la même souche et sont certainement différents des occidentaux. A partir de cela et d'autres éléments, nous concluons que tous les Hypera des USA sont H. postica Gyllenhal et que l'utilisation d'H. brunneipennis Boheman pour désigner les Hypera ‘égyptiens’ d'Amérique du Nord doit être abandonnée.
    Notes: Abstract Allozyme profiles of eastern weevils (Beltsville, Maryland; Washington Co., Illinois), western weevils (Logan and St. George, Utah), and Egyptian weevils (Yuma, Arizona; Westmorland, California) were compiled by acrylamide gel electrophoresis. Twenty-two gene loci from 12 enzymes (ACPH, ADH, AMY, AO, EST, GOT, G-6PDH, MDH, ME, SOD, TYR, XDH) were analyzed. Mean heterozygosity of these populations was 0.231, with an average proportion of polymorphic loci of 0.536. The mean genetic distance of all weevil populations was 0.033 and the fixation index was 0.024. Diagnostic loci were found which could distinguish western weevils from eastern and Egyptian weevils. The small genetic distance between the eastern and Egyptian weevils suggests that they may be the same strain and are certainly different from the western weevil strain. Based on this and other evidence, we conclude that all weevil strains in the United States are Hypera postica (Gyllenhal), and that the use of H. brunneipennis (Boheman) for the Egyptian alfalfa weevil of North America should be discontinued.
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    Entomologia experimentalis et applicata 34 (1983), S. 291-296 
    ISSN: 1570-7458
    Keywords: Coleoptera ; Curculionidae ; Cyrtobagous ; Salvinia weevil ; Feeding characteristics of larvae ; Development of larvae ; Plant nutrition ; Temperature effects on development
    Source: Springer Online Journal Archives 1860-2000
    Topics: Biology
    Description / Table of Contents: Résumé Après leur naissance, les larves de Cyrtobagous sp. passent de 1 à 4 jours à brouter les racines, et de 0 à 9 jours dans les bourgeons de la plante hôte, Salvinia molesta, avant d'y creuser une galerie dans le rhizome. Bien que les larves aient été capables de survivre jusqu'à 38 jours en broutant les racines, quant elles furent privées de rhizome, elle ne purent achever leur développement. Quand les galeries furent commencées, le développement larvaire, entre 21° et 31°, dépendit de la température et de la teneur en azote de l'hôte. Les larves ne se développèrent pas à 17°. Une haute valeur nutritive de l'aliment consommé par les larves réduisit la durée du développement, mais n'influença pas la durée ultérieure de leur développement nymphal. Les lieux de prise de nourriture et les dégâts produits par des larves isolées furent précisés.
    Notes: Abstract Newly-emerged larvae of a salvinia weevil, Cyrtobagous sp. spent from 1–4 days browsing on the roots and from 0–9 days in the buds of the host plant, Salvinia molesta, prior to tunnelling into the rhizome of this aquatic weed. Although larvae were able to survive up to 38 days browsing on roots when rhizomes were withheld, they were unable to complete development. After tunnelling began, larval development between 21° and 31° was dependent on temperature and nitrogen levels in the host. Larvae failed to develop at 17°. High nutritional intake by the larvae reduced larval development time but did not influence duration of their subsequent pupal development. The feeding sites and plant damage produced by individual larvae were assessed.
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  • 21
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    Entomologia experimentalis et applicata 37 (1985), S. 229-233 
    ISSN: 1570-7458
    Keywords: alfalfa weevil ; Coleoptera ; Curculionidae ; Hypera postica ; mutation ; vestigial-wing
    Source: Springer Online Journal Archives 1860-2000
    Topics: Biology
    Description / Table of Contents: Résumé Des H. postica aux ailes postérieures vestigiales ont été découverts dans une population de Wageningen (Pays Bas) et deux des USA—une lignée orientale de Beltsville (Maryland) et une lignée de H. brunneipennis d'Atascadero (Californie). Ce mutant était absent de 23 autres populations examinées aux USA: 3 de l'est, 7 de l'ouest et 13 de H. brunneipennis. Cette mutation est due à un gène dominant antosomal avec aile normale comme récessif. Le gêne mutant peut être transféré des lignées orientales aux lignées occidentales. Le caractère aile courte peut être pratique pour les manipulations génétiques destinées à maîtriser les populations d'H. postica.
    Notes: Abstract Alfalfa weevils (Hypera postica (Gyllenhal)) with vestigial hind wings were discovered in a population from Wageningen, the Netherlands, and two populations from the United States—an eastern weevil strain from Beltsville, Maryland and an Egyptian weevil strain from Atascadero, California. Such a mutant was absent from 23 other populations surveyed in the United States—three from eastern, seven from western, and 13 from Egyptian weevil strains. This mutation is due to a dominant autosomal gene with normal-wing individuals as recessive. The mutant gene can be transferred from eastern weevil to the western weevil strain. The short-wing trait may be useful for genetic manipulation to control the alfalfa weevil.
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  • 22
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    Entomologia experimentalis et applicata 44 (1987), S. 187-193 
    ISSN: 1570-7458
    Keywords: Calosoma sycophanta ; Carabidae ; Coleoptera ; emigration ; gypsy moth ; Lymantria dispar ; spatial dispersion
    Source: Springer Online Journal Archives 1860-2000
    Topics: Biology
    Description / Table of Contents: Résumé L'étude par capture-recapture de Calosoma sycophanta L. (Carabidae) a été effectuée dans deux parcelles de 4 ha en utilisant des pièges distribués sur une grille de 10 sur 10. Pendant la première année d'échantillonnage, Lymantria dispar L. (Lymantriidae) était abondant et les calosomes se sont reproduits, tandis que la seconde année les papillons étaient beaucoup moins nombreux. La distribution des larves de carabes a été examinée aussi pendant la première année sur l'une des stations, et celle des chenilles pendant les deux années avec des toiles d'emballage sur l'autre station. Les dispersions des adultes et larves de calosomes et des chenilles de Lymantria ont été calculées en utilisant la régression du logarithme naturel de la variance de l'échantillon sur le logarithme naturel de la moyenne (méthode de Taylor) et la régression de l'indice de Lloyd d'agrégation moyenne sur la moyenne (méthode d'Iwao). La méthode de Taylor a donné les résultats les plus logiques, et les pentes ont servi à mesurer le degré d'agrégation. Les recaptures de calosomes adultes ont été analysées par les méthodes de Fisher-Ford et Jolly-Seber, associées à la méthode de Jackson pour séparer survie et migration. De même, une nouvelle méthode pour déterminer directement la migration en découvrant combien d'insectes recapturés ont abandonné les microparcelles s'est révélée comme la plus cohérente avec le procédé Fisher-Ford-Jackson. La tendance à l'agrégation est plus forte chez les mâles (d'après la pente du logarithme de la moyenne par rapport au logarithm e de la variance de l'échantillon). La migration et le degré d'agrégation paraissent varier ensemble dans une station, tandis que dans l'autre une telle relation n'apparaît pas clairement. Les femelles malgré des taux de migration variés mais généralement faibles, n'ont jamais pr'esenté de tendance significative à l'agrégation. A l'opposé, les larves de calosomes et de Lymantria ont presenté des distributions agrégatives.
    Notes: Abstract Mark-release studies of Calosoma sycophanta L. (Carabidae) in two 40000 m2 areas were done using traps deployed in 10 by 10 grids. In both areas, gypsy moths, Lymantria dispar L. (Lymantriidae), were abundant the first but not the second year of sampling. The distribution of carabid larvae was also investigated in the first year at one of the sites and the distribution of gypsy moth larvae found under burlap bands determined for 2 years at the other site. Dispersions of beetles and prey were evaluated by Taylor's logarithmic meanvariance method and Iwao's mean-mean crowding method. Taylor's method gave the most consistent results, and the slopes of the regression lines were used to determine degree of clumping. To evaluate dispersal of adult beetles, recapture data were analysed using the Fisher-Ford and Jolly-Seber methods in conjunction with Jackson's method for separating survival and emigration. A new method for estimating emigration was found to be most consistent with the Fisher-Ford-Jackson procedure. The tendency of the beetles to aggregate (measured via Taylor's method) was generally highest for males. In one site, emigration and degree of aggregation for males appeared to vary together, while at the other site no relationship was evident. Females showed few tendencies to aggregate. Both beetle larvae and gypsy moth larvae had clumped distributions.
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    Entomologia experimentalis et applicata 45 (1987), S. 102-104 
    ISSN: 1570-7458
    Keywords: Coleoptera ; Carabidae ; Bembidion ; Trechus ; Agonum ; sex determination ; adhesion ; male setae ; tarsomere
    Source: Springer Online Journal Archives 1860-2000
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  • 24
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    Entomologia experimentalis et applicata 39 (1985), S. 223-232 
    ISSN: 1570-7458
    Keywords: Onitis alexis ; Coleoptera ; Scarabaeinae ; dung beetle ; crepuscular flight ; superposition eyes
    Source: Springer Online Journal Archives 1860-2000
    Topics: Biology
    Description / Table of Contents: Résumé L'examen a porté sur le rôle de l'intensité lumineuse et de la température sur l'incitation au vol chez Onitis alexis. Le vol en lumière naturelle est fortement synchronisé, avec les deux tiers des adultes qui s'envolent en 10–12 min. Sur six vols pour différents jours, le moment moyen d'envol variait de 13 min, mais l'envol moyen avait lieu à une intensité lumineuse déterminée. La valeur absolue de l'intensité lumineuse paraît ainsi un signal crucial dans la détermination et l'incitation au vol. Le moment d'envol se maintient à cette intensité quand le crépuscule est artificiellement avancé jusqu'à 8 min environ. Cependant, quand le crépuscule est rendu encore plus précoce, l'envol moyen se produit à des intensités plus basses et est étalé. Ceci peut être interprété comme un chevauchement de la période des intensités lumineuses favorables à l'envol avec le rythme circadien qui conduit les bousiers à la surface. Aucun adulte ne vole quand il y a maintien de lumière constante ou d'obscurité à l'heure du crépuscule. En présence de crépuscule constant, les réponses sont hétérogènes, et, bien que le moment médian d'envol ne soit retardé que de 3 min, par rapport aux témoins, l'incitation à l'envol est étalée sur une période plus longue. Avec des températures au sol de 20–22 °C, plus de 90% des adultes s'envolent. Le pourcentage diminue avec la température, et moins de 10% s'envolent à 16–17 °C.
    Notes: Abstract The role of light intensity and temperature in determining the onset of flight in the crepuscular dung beetle Onitis alexis Klug (Coleoptera: Scarabaeidae) was examined. Flight under natural light was highly synchronized, with two-thirds of the beetles that flew flying over a period of 10–12 min. In six flights on different days, the mean time of onset varied by up to 13 min, but mean onset occurred at fixed light intensity. Absolute light intensity therefore appears to be a vital cue in determining flight onset. Mean onset remained at this intensity when dusk was advanced artificially by up to about 8 min. However, when dusk was brought further forward, mean flight occurred at lower intensities and onset of flight took place over a longer period. This is interpreted as an overlapping of the period of light intensities suitable for flight with the circadian rhythm that brings the beetles to the surface. No beetles flew when kept under constant bright light or in the dark during the dusk period. Under conditions of constant dusk, the beetles appeared uncoordinated and, although the median time of onset of flight was only 3 min later than in the control flight, onset of flight was spread out over a much longer period. At soil temperatures of 20–22 °C, over 90% of the beetles flew. This percentage decreased with decreasing temperature, and less than 10% flew at temperatures of 16–17 °C.
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    Entomologia experimentalis et applicata 40 (1986), S. 81-88 
    ISSN: 1570-7458
    Keywords: Ips typographus ; spruce bark beetle ; Coleoptera ; Scolytidae ; model ; reemergence ; density dependent ; temperature dependent ; degree-days ; poikilotherm
    Source: Springer Online Journal Archives 1860-2000
    Topics: Biology
    Description / Table of Contents: Résumé Ce modèle décrit la réémergence d'adultes d'I. typographus L. (Coleoptera, Scolytidae) en fonction de la densité et de la température. Les résultats obtenus en laboratoire à des températures constantes fournissent la distribution des réémergences et pour les dates de réémergence moyenne les différentes combinaisons de température de seuil et de degré de jour (°D). De toutes ces combinaisons, 167.71 °D au-dessus de 7,5 °C fournit la meilleure concordance entre les prévisions du modèle et les observations dans la nature à partir d'arbres fortement attaqués. Le modèle a montré un bon accord avec la réémergence observée dans deux groupes de branches attaquées dans différentes conditions de la température quand il a été ajusté aux faibles densités d'élevage. La discussion examine les possibilités d'application du modèle à l'étude de la biologie de la reproduction d'I. typographus et à l'aménagement forestier. La méthode utilisée pour construire le modèle pourrait être employée pour en développer d'autres chez des poikilothermes.
    Notes: Abstract A model is presented that describes the reemergence of parent spruce bark beetles, Ips typographus, based on breeding density and temperature conditions. Laboratory data obtained at one constant temperature provide the distribution of reemergence time and different combinations of threshold temperatures and degreedays (°D) at mean reemergence. Of these combinations, 167.71 °D above 7.5 °C gave the best correspondence between model prediction and field data obtained from densely infested standing trees. The model was in good agreement with the reemergence pattern found for two groups of infested logs under different temperature conditions when adjusted for the lower breeding density. The applicability of the model in the study of bark beetle reproductive biology and in forest management is discussed. The method used to construct the model should be useful in developing other models for poikilothermic processes.
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    Entomologia experimentalis et applicata 47 (1988), S. 173-182 
    ISSN: 1570-7458
    Keywords: Bembidion lampros ; Pterostichus cupreus ; Carabidae ; Coleoptera ; behaviour ; temperature ; searching ; consumption ; cereal aphid ; Rhopalosiphum padi ; prey ; density ; barley
    Source: Springer Online Journal Archives 1860-2000
    Topics: Biology
    Description / Table of Contents: Résumé Les taux maximum de consommation de R. padi L. à différentes températures ont été déterminés au laboratoire chez deux carabes, B. lampros Herbstet P. cupreus L. La consommation moyenne a augmenté avec la température chez les deux espèces, B. lampros consommant un maximum de 15,9 larves des stades 1 à 3 et 9,1 pucerons adultes aptères, à 25°C. P. cupreus a été particulièrement vorace et a consommé 125,3 adultes aptères par jour à 20°C. Le comportement des deux espèces a été observé en filmant en vidéo des carabes à jeun, maintenus à différentes températures constantes, dans des enceintes semées en orge de printemps. Des éléments du comportement, communs aux deux espèces, ont été définis: 1) immabilité, 2) marche et course, 3) recherche, 4) affrontement. P. cupreus a été plus actif à toutes les températures, B. lamprosa été inactif au-dessous de 10°C. La part de temps consacrée à la recherche, le nombre de plantes prospectées, et la vitesse ont augmenté avec la température chez les deux espèces. Dans des enceintes similaires colonisées par R. padi, P. cupreus a significativement augmenté le temps consacré à la recherche dans les enceintes, parallèlement à l'augmentation de la densité des pucerons. Après la découverte d'une colonie de pucerons, P. cupreus escalade et prospecte la plante et ses voisines immédiates; tandis que les plantes des enceintes sans pucerons sont rarement escaladées. B. lampros n'a pas été observé escaladant des plantes d'enceintes avec ou sans pucerons, et il n'a pas accru son temps de prospection en fonction de la densité de pucerons. Les quelques B. lampros qui ont capturé des pucerons l'ont fait lorsque ceux-ci marchaient sur la surface du sol. La discussion a porté sur l'efficacité relative des deux carabes comme prédateurs de R. padi, et les résultats ont été comparés à ceux d'études du même type, menées ailleurs, avec des prédateurs de Sitobion avenae sur blé d'hiver.
    Notes: Abstract Maximum consumption rates were determined for two carabids, Bembidion lampros Herbst. and Pterostichus cupreus L., feeding on the cereal aphid Rhopalosiphum padi L. at different temperatures in the laboratory. Mean daily consumption increased with increasing temperature for both species, B. lampros consuming a maximum of 16 1–3 instar nymphs and 9 apterous adult aphids at 25°C. P. cupreus was particularly voracious and consumed 125 apterous adult R. padi per day at 20°C. The behaviour of both species was analysed by video filming starved beetles, maintained at different constant temperatures, in arenas sown with spring barley. The behavioural components (1) still; (2) run/walk; (3) search and (4) confrontation were identified and were common to both species. P. cupreus was more active over the temperature range tested; B. lampros was inactive under 10°C. The proportion of time spent searching, number of plants searched, and velocity increased with increasing temperature for both species. When observed in similar arenas seeded with R. padi colonies, individuals of P. cupreus significantly increased their time spent searching in arenas with increasing aphid density. Following discovery of an aphid colony, individuals climbed and searched the host plant and its nearest neighbours. Plants in aphid free arenas were rarely climbed. B. lampros was not observed climbing in either aphid free arenas or in arenas with increasing aphid densities, and did not significantly increase its time spent searching in response to increased prey density. The few B. lampros that found aphids caught them walking on the soil surface. The relative efficiences of these two carabids as predators of R. padi are discussed, and the results are compared with similar studies elsewhere with predators of Sitobion avenae on winter wheat.
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    Entomologia experimentalis et applicata 48 (1988), S. 43-50 
    ISSN: 1570-7458
    Keywords: Coleoptera ; Carabidae ; Pterostichus ; mandible size ; wear pattern ; feeding behaviour ; burrowing
    Source: Springer Online Journal Archives 1860-2000
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    Description / Table of Contents: Résumé L'analyse de l'influence de la texture des aliments et du fouissage, sur l'usure des mandibules a été effectuée en nourrissant P. melanarius avec des aliments de différentes duretés dans des récipients contenant ou non du sol. Les aliments durs seuls usent moins le bord incisif (extrémité de la mandibule) et la surface coupante, que leur association avec le fouissage. En présence exclusive d'aliments durs, les femelles avaient érodé plus vite leurs mandibules que les mâles, tandis que chez ceux-ci le fouissage seul les avaient usé plus vite que chez les femelles. Des femelles récoltées dans un champ de céréales contenaient plus d'aliments durs que les mâles. Les différences de comportement avaient provoqué apparemment des types d'usure différents suivant les sexes. Les adultes usent leurs mandibules au cours de leur première année de vie imaginale. Cependant, la taille des mandibules des femelles échantillonnées dans la nature correspondait mieux à celle des femelles (de même âge) provenant des expériences ayant provoqué une forte usure (aliment dur et fouissage du sol). Les mandibules des mâles échantillonnés présentaient seulement une usure modérée et ressemblaient à celles des mâles ayant consommé soit des aliments durs, soit foui le sol. La discussion a traité des relations entre l'usure des mandibules, la fécondité et la longévité de P. melanarius et d'autres espèces de carabes.
    Notes: Abstract The effects of food texture and burrowing on mandible wear in the predatory carabid beetle Pterostichus melanarius Illiger were investigated by feeding adults soft or hard food in jars with or without soil. Both the incisor cusp (mandible tip) and cutting surface of the mandibles erode more in response to the combination of hard food and burrowing than to hard food alone. Females were found to erode their mandibles more than males in the hard-food-only treatment, whereas males wore down their mandibles more than females in the soil-only treatment. Female P. melanarius collected in a cereal field contained signficantly more solid food items compared with males. Differences in behaviour apparently resulted in differential wear patterns between the sexes. It is shown that the process of mandible wear in P. melanarius will result in worn mandibles in their first year as adults. However, mandible size of field-sampled females were found to be best correlated with females (of similar age) in the experiment exhibiting extensive wear (foraged hard food and burrowed in soil). The mandibles of field-sampled males were similar to those of males in the hard-food-only and the soil-only treatments, which showed only slight to moderate wear. The influence of mandible wear on fecundity and survival in P. melanarius as well as in other carabid species is discussed.
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    ISSN: 1570-7458
    Keywords: Coleoptera ; Cerambycidae ; Morimus funereus ; development ; laboratory conditions ; food quality ; temperature ; season
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    Description / Table of Contents: Résumé L'étude a porté sur les effets d'une température constante (23 °C), de la qualité de l'aliment,-B = aliment naturel, c'est-à-dire de l'écorce de chêne pulvérisée; B+C = aliment naturel enrichi avec de la poudre de biscuits sucrés-, et de la saison sur le développement larvaire de M. funereus L. La température de 23 °C a été défavorable aux larves récoltées en septembre dans des souches de chênes et élevées sur aliment B: les larves étaient mortes en 30 jours. Avec aliment B+C, l'effet défavorable a été neutralisé et le poids des larves augmenté de 543%, 897% et 1179% en 1, 2 et 3 mois. Des larves néonates d'été ou d'hiver se sont bien développées sur B+C, mais toutes les larves d'hiver étaient mortes sur B en 40 j. Des larves de mêmes parents, écloses à différentes époques de l'année, ont présenté des différences saisonnières du taux de survie et de la vitesse de développement lors de leur élevage à 23 °C sur B+C. Le développement le plus rapide et la meilleure survie ont été obtenus avec des larves écloses au début ou au milieu de l'été; tandis que le développement le plus lent et la plus mauvaise survie ont été obtenus avec les larves écloses à la fin de l'été. Les changements saisonniers synchrones des adultes et de leurs descendants, exprimés à différents niveaux d'organisation biologique, suggèrent l'existence d'un rythme annuel endogène qui dépend de l'expression de différents gènes au cours du cycle annuel.
    Notes: Abstract The effects of constant temperature (23 °C), food quality (B, natural diet i.e. powdered oak bark; B+C, natural diet enriched with powdered sweet crackers) and season on larval development of the cerambycid Morimus funereus L. were studied. The temperature of 23 °C exerted an unfavourable effect on larvae collected from oak stumps in September and bred on B; i.e. the larvae died within 30 days. When the larvae consumed B+C the unfavourable effect of temperature was abolished and the larvae increased their weight by 543%, 897% and 1179% in 1, 2 and 3 months, respectively. Newly hatched summerand winter-larvae developed successfully on B+C, while all the winter-larvae died within 40 days on B. Larvae of an identical parentage hatched in different phases of the annual cycle and showed seasonal differences in the rate of development and survival when reared on B+C at 23 °C. The fastest development and the highest survival rate were observed in larvae which emerged in early- and midsummer, whereas the slowest development and the lowest survival rate were in those hatched in late summer. The synchronized seasonal changes of adults and their offspring, as expressed at different levels of biological organization, suggest the existence of an endogenous annual rhythm which is dependent upon the expression of different genes in the course of the annual cycle.
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    ISSN: 1570-7458
    Keywords: Diabrotica spp. ; corn rootworms ; Chrysomelidae ; Coleoptera ; plant-derived semiochemicals ; starch matrix ; encapsulation ; controlled release
    Source: Springer Online Journal Archives 1860-2000
    Topics: Biology
    Description / Table of Contents: Résumé Le programme expérimental de 1987 était destiné à déterminer: 1) si les substances dérivées de végétaux et attractives pour Diabrotica pouvaient être encapsulées dans de l'amidon additionné d'acide borique; 2) si différentes formules attireraient les différentes espèces de Diabrotica dans un champ de maïs. L'indol, l'estragol, le vératrol, le phénylacétaldéhyde et le trans-anéthol n'ont pas été retenus, tandis que le trans-cinnamaldéhyde, la \-ionone, le 1,2,4-triméthobenzène, l'eugénol et l'isœugénol ont été encapsulés avec succès dans des pièges attachés à des pieds de maïs (les détails techniques sont fournis). Les pièges ont été relevés tous les 4 jours du 11 juillet au 8 septembre. Les résultats montrent que les substances allélochimiques sont conservées dans la capsule pendant des durées variables et libérées à des concentrations attractives pour les Diabrotica adultes. Un mélange de trans-cinnamaldéhyde et de 1,2,4,-triméthoxybenzène a été la formule la plus efficace, à l'exception des périodes de formation des barbes et du pollen, où aucune formule n'a été attractive. Bien que la variation saisonnière des réactions de Diabrotica limite l'utilisation des substances allélochimiques d'origine végétale, la capsule d'amidon peut être employée pour libérer des substances allélochimiques et constitue un outil potentiel pour la mise au point d'une méthode plus rationnelle de lutte contre Diabrotica.
    Notes: Abstract The concept of encapsulating semiochemicals into a starch matrix is being studied for potential use in corn rootworm (CRW) management programs. During 1987, experiments were conducted to determine: 1) If volatile plant-derived Diabrotica spp. attractants could be encapsulated in a starch borate matrix (SBM), and 2) If various SBM-semiochemical formulations would attract Diabrotica species over time in field corn. Chemical analyses of fresh SBM formulations indicated that indole, estragole, veratrole, phenylacetaldehyde, and trans-anethole were not retained during formulation but trans-cinnamaldehyde, Beta-ionone, 1,2,4,-trimethoxybenzene, eugenol and isœugenol were successfully encapsulated. Encapsulated semiochemical formulations were made into 20 mesh granules, placed in Pherocon ® 1C traps that were tied to corn plants, and sampled for CRW adults every 4 days from 11 July to 8 September. Field data indicated that encapsulated semiochemicals were retained in the SBM for varying lengths of time and were released at rates attractive to CRW adults. A two-component mixture of trans-cinnamaldehyde and 1,2,4-trimethoxybenzene was the most effective formulation tested; however, no formulation was effective during corn silking and pollination. Although seasonal variation in CRW response could limit the usefulness of some plant-derived semiochemicals, the starch matrix concept may be useful as a delivery system for semiochemicals and may have potential as a tool that could be used in the development of new more biorational CRW management programs.
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    Entomologia experimentalis et applicata 50 (1989), S. 61-67 
    ISSN: 1570-7458
    Keywords: Coleoptera ; Chrysomelidae ; northern corn rootworm ; western corn rootworm ; dispersal ; malaise trap ; habitat selection
    Source: Springer Online Journal Archives 1860-2000
    Topics: Biology
    Description / Table of Contents: Résumé Les activités de vol de D. barberi (NCR) et D. virgifera virgifera (WCR) ont été contrôlées par l'utilisation de pièges ‘malais’ placés en lisière de deux petits champs de maïs. Les populations de ces coléoptères sont maximales quand le maïs fleurit, mais leurs captures sont restées faibles jusqu'à ce que les barbes du maïs aient été sèches. Les captures de NCR et, dans une plus faible mesure, celles de WCR ont alors augmenté et sont restées importantes pendant toute la saison. Les pièges ‘malais’ ont été conçus pour que les adultes pénétrant par les côtés opposés soient récoltés séparément. Les femelles de NCR capturées face au champ de maïs avaient tendance à contenir moins d'ovocytes mûrs que celles capturées du côté opposé. Ces observations appuient l'hypothèse que les femelles NCR émigrent des champs de maïs pour s'alimenter, quand les barbes et le pollen de maïs, aliments préférés, deviennent indisponibles, mais que les femelles NCR pleines d'ovocytes mûrs recherchent le maïs quand elles sont en quête de lieux de ponte.
    Notes: Abstract Flight activity of corn rootworm beetles, the northern (NCR), Diabrotica barberi (Coleoptera: Chrysomelidae), and western (WCR), D. virgifera virgifera, was monitored using malaise traps placed at the edges of two small cornfields. Populations of beetles in the fields peaked while corn was flowering, but capture in malaise traps remained low until silks had dried. Capture of NCR and (to a lesser extent) WCR then increased and remained high through the season. Malaise traps were constructed to permit separate collections of beetles that entered on each of two opposite sides. Female NCR that were captured in sides that faced toward corn tended to contain fewer mature eggs than those in sides facing away from corn. These findings support the hypothesis that female NCR emigrate from cornfields to feed when fresh silk and corn pollen (favored foods) become unavailable, but that egg-laden NCR actively seek corn when searching for oviposition sites.
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  • 31
    ISSN: 1570-7458
    Keywords: Coleoptera ; Curculionidae ; Cylas formicarius elegantulus ; sweetpotato weevil ; sweet potato ; digestion ; enzyme distribution ; trypsin-inhibitors ; resistance
    Source: Springer Online Journal Archives 1860-2000
    Topics: Biology
    Description / Table of Contents: Résumé L'activité endoprotéinase était limitée au liquide de la lumière des régions ventriculaires antérieure et postérieure de l'intestin moyen des larves deCylas formicarius elegantulus Summers. Les aminopeptidases ont été trouvées dans le liquide de la lumière (18%), mais étaient principalement associées avec les fractions insolubles des cellules du ventricule postérieur (82%). Suivant le substrat, l'activité carboxypeptidase était à peu près également répartie entre le liquide de la lumière et les fractions insolubles des cellules du ventricule postérieur. L'amylase, enzyme secrétée, a été observée à la fois dans la lumière antérieure et postérieure. Cinq bandes d'activité amylase ont été révélées sur zymogrammes d'amidon après électrophorèse d'intestins moyens entiers. Trois des bandes d'amylase pouvaient provenir de la plante. Il y avait au moins 2 α-glucosidases, une secrétée et une liée aux cellules du ventricule antérieur. L'activite β-glucosidase était liée aux cellules du ventricule antérieur, fandis que l'activité α-galactosidase était limitée au fluide de la lumière. Les activités β-galactosidase et cellulase ont été trouvées à la fois dans le liquide de la lumière et dans la fraction cellulaire insoluble. Ainsi, la digestion initiale des grosses protéines et des polymères de carbohydrates se produit dans le liquide de la lumière dans les régions ventriculaires antérieure et postérieure. Cependant, l'achèvement de la digestion des oligopeptides se produit principalement dans le ventricule postérieur, tandis que la fin de la digestion des oligosaccharides se produit dans le ventricule antérieur. Les concentrations en inhibiteurs de trypsine de 5 cultivars d'I. batatas L. diffèrent de 1 à 20. Les endoprotéinases deC. formicarius elegantulus ont été inhibées par des extraits de cultivars, mais les cultivars avec des concentrations relativement élevées d'inhibiteur avainent antérieurement montré être susceptibles d'être attaqués par le coléoptère dans des essais en champs.
    Notes: Abstract Endoproteinase activity was confined to luminal fluid from anterior and posterior ventricular regions of midguts of larvae of the sweetpotato weevil,Cylas formicarius elegantulus (Summers). Aminopeptidase was found in luminal fluid (18%) but was primarily associated with insoluble fractions from cells of the posterior ventriculus (82%). Depending on substrate, carboxypeptidase activity was about equally distributed between luminal fluid and insoluble fractions from posterior ventriculus cells. Amylase was found in luminal fluid in both the anterior and posterior ventriculus. Five bands of amylase activity were detected on starch zymograms following electrophoresis of whole midgut samples. Three of the amylase bands may be plant-derived. At least two α-glucosidases were present, one secreted and one bound to anterior ventriculus cells. β-Glucosidase activity was bound to anterior ventriculus cells whereas α-galactosidase activity was confined to luminal fluid. β-Galactosidase and cellulase activities were found in both luminal fluid and the insoluble cell fraction. Thus, initial digestion of large protein and carbohydrate polymers occurs in luminal fluid in both anterior and posterior ventriculus regions. However, terminal digestion of oligopeptides occurs primarily in the posterior ventriculus while terminal digestion of oligosaccharides occurs in the anterior ventriculus. A 20-fold difference in trypsin-inhibitor concentration was found among five sweetpotato cultivars. Endoproteinases from sweetpotato weevil larvae were inhibited by extracts from the cultivars but cultivars with relatively high concentrations of inhibitor were previously shown to be susceptible to weevil attack in field trials.
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  • 32
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    Entomologia experimentalis et applicata 37 (1985), S. 123-127 
    ISSN: 1570-7458
    Keywords: Coleoptera ; Carabidae ; Poecilus cupreus ; larva ; starvation ; digestion ; enzyme-linked immunosorbent assay
    Source: Springer Online Journal Archives 1860-2000
    Topics: Biology
    Description / Table of Contents: Zusammenfassung Mit eine quantitativen enzymabhängigen Immunoabsorptionstest wurde immunoreaktives Material aus Beutetieren als Eiweissgehalt (IRM/P) in Larven eines polyphagen räuberischen Carabiden, Poecilus cupreus, bestimmt. Wir bestimmten den Beuteverzehr und die Geschwindigkeit des IRM/P Abbaus bei Larven, die während verschiedener Zeit gehungert hatten. Der Beuteverzehr nahm exponentiell zu über 7 Tage Hunger. Die Geschwindigkeit des Beute- IRM/P Abbaus schien logarithmisch. Die Beuteaufnahme nahm fast zwanzigfach zu über 7 Tage Hunger von 2.7 ng auf 50.2 ng IRM/P/10 Mikroliter Larvenextrakt. Der grösste Teil der Verdauung erfolgte am zweiten bis dritten Tag nach der Nahrungsaufnahme, unabhängig von der verdauten Menge. Das Niveau 4 Tage nach der Fütterung zeigte, dass Larven, die vorgängig 7 Tage gehungert hatten, 5.0 ng IRM/P/10 Microliter Extrakt zurückhielten; dies war mehr als die Aufnahmemenge nichthungernder Larven. Die Verdauungsgeschwindigleit nahm zu mit der Dauer des Hungerns, doch wurde auch mehr Beute im Nahrungskanal zurückgehalten.
    Notes: Abstract Prey antigen levels were determined by a quantitative enzyme-linked immunosorbent assay in larvae of a carabid predator, Poecilus cupreus L. under laboratory conditions. We determined prey consumption and rate of prey protein decay in larvae having starved for different periods. Prey consumption increased exponentially over 7 days of starvation. The rate of prey immunoreactive material decay seemed to be logarithmic, similar in larvae which had starved for different periods. Most of the digestion took place in the first 3 days period after feeding, irrespective of the amounts ingested. The rate of decay increased with increasing period of starvation. There were also signs of food retention in the alimentary canal in larvae which starved longer.
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    Entomologia experimentalis et applicata 42 (1986), S. 201-212 
    ISSN: 1570-7458
    Keywords: Callosobruchus maculatus ; Bruchidae ; Coleoptera ; behavior ; evolution ; genetic variation ; insect-plant interactions ; oviposition preference
    Source: Springer Online Journal Archives 1860-2000
    Topics: Biology
    Description / Table of Contents: Résumé Vingt-deux lignées deC. maculatus Fab., liées à 6 plantes-hôtes, ont été examinées quant à leurs préférences — sans choix—parmi les graines de 9 légumineuses. Ces préférences se sont révél'ees semblables à celles observées lors de choix binaires; 3 paramètres ont donné les mêmes résultats: nombre moyen d'oeufs pondus par l'ensemble des femelles, nombre moyen d'oeufs émis par l'ensemble de celles acceptant la plante, fréquence des femelles acceptant la plante. L'analyse en composantes principales des préférences pour les 9 plantes a révélé que la majorité des mesures se situe sur les 2 premiers axes, qui ont rendu compte de 89% de la variation. Les performances des lignées sur le premier axe suggèrent qu'il s'agit d'un critère général de préférence. La classification automatique des plantes a montré un aspect général semblable à celui des composantes principales. Par ces 2 méthodes, les plantes ne se sont pas classées nettement selon leurs affinités taxonomiques. Bien que la classification automatique n'ait pas mis en évidence une similarité de comportement chez les insectes liés au même hôte, ceci était apparemment le cas. Les lignées liées à des hôtes présentant de fortes — ou à l'opoosé — de faibles préférences, ont montré différents seuils d'acceptation pour les 9 substrats de ponte. A l'opposé, il n'y a aucune preuve d'altération évolutive de la hiérarchie de préférences. On en a déduit que ces insectes étaient motivés par un petit nombre de stimulus, tels que les allélochimiques et al texture de tégument, pour déceler l'adéquation des substrats potentiels. (La microscopie électronique a suggéré une corrélation entre la texture du tégument et la hiérarchie des préférences de ces populations). La confiance dans les stimulus recueillis contribue à limiter les stratégies évolutives disponibles pour la population. A partir de là, la sélection en faveur —ou contre — des plantes, à l'origine, faiblement préférées, peut conduire, dans la niche de ponte, à l'incorporation — ou à l'exclusion — d'un groupe d'espèces taxonomiquemment éloignées, mais phénétiquement semblables. La probabilité d'altérations importantes de la hiérarchie des préférences paraît extrémement faible.
    Notes: Abstract A survey of 22 strains ofCallosobruchus maculatus associated with six different leguminous hosts indicates extensive genetic differentiation for oviposition preference. Female behavior suggests the existence of two distinct host preference groups among the nine oviposition substrates tested. Strains associated with plants in these two groups show distinct preference profiles. Genetic differentiation of oviposition preference is due to evolutionary modification of the threshold of acceptance of host plants, not to alteration of the preference hierarchy. From principal components analysis of these results, it is likely that very few independent plant traits govern oviposition preference.
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  • 34
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    Entomologia experimentalis et applicata 45 (1987), S. 23-27 
    ISSN: 1570-7458
    Keywords: Coléoptère ; Bruchidae ; Olfactométrie ; phéromone sexuelle ; plante hôte ; régulation de la réproduction ; Coleoptera ; Bruchidae ; olfactometer ; sex pheromone ; host plant ; reproductive regulation
    Source: Springer Online Journal Archives 1860-2000
    Topics: Biology
    Description / Table of Contents: Summary In order to meet its sexual partner, Zabrotes subfasciatus must rely on the olfactory signals emitted either by the female or the male insect. The attractiveness of male and female odours were therefore studied and compared in an olfactometer. The behaviour of virgin and inseminated females and males, left in contact with the host plant's seeds or not, was studied in terms of the age of the imagos. In all cases examined, male odours did not attract female insects. Virgin females kept without seeds of the host plant did not attract males. On the other hand, the odour of virgin females left in contact with bean seeds significantly attracted virgin males. The females' attractive power varied according to their age: older females released a chemical cue that was more attractive for the males. Emission of the sex-pheromone stops after insemination of the females but begins again after a certain period of time. Results are discussed in terms of what is known on the reproductive regulation of this bruchid.
    Notes: Abstract Pour rechercher son partenaire sexuel Zabrotes subfasciatus doit utiliser les signaux olfactifs émis soit par les mâles ou par les femelles. Le pouvoir attractif de l'odeur des mâles et des femelles sont donc étudiés et comparés par olfactométrie. Le comportement de mâles et de femelles vierges et inséminées, mis en contact des graines de la plante hôte ou non, est observé en fonction de l'âge des imagos. En aucun cas, les odeurs des mâles n'exercent une attraction sur les femelles. Les femelles vierges en absence de graines de haricot (Phaseolus vulgaris) n'exercent pas d'attraction sur les mâles vierges. Par contre les odeurs des femelles vierges mises en contact avec les graines de haricot sont très attractives pour les mâles vierges et varie en fonction de l'âge: il est plus affirmé chez les femelles plus âgées. L'émission de la phéromone sexuelle est interrompue après l'insémination des femelles mais reprend au bout d'un certain temps après celle-ci.
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  • 35
    ISSN: 1570-7458
    Keywords: body weight ; flight ; Ips calligraphus ; lipid ; longevity ; phloem ; pine ; Scolytidae ; Coleoptera
    Source: Springer Online Journal Archives 1860-2000
    Topics: Biology
    Description / Table of Contents: Résumé Le comportement de vol d'Ips calligraphus GERMAR (Scolytidae) a été examiné au laboratoire par une technique de vol captif. La génération parentale avait été artificiellement introduite, suivant la taille des adultes (1,6 à 2,1 mm) dans des morceaux de Pinus elliottii Engelm. variété elliottii au phloeme épais (TK=2,5 à 3,5 mm) ou fin (TN=0,5 à 1,5 mm) les larves se sont développées dans ces morceaux de pin. Le poids et la teneur en lipide des adultes obtenus à partir de TN étaient significativement inférieure à ceux de TK. Le poids des mâles les plus gros a été plus réduit que celui des femelles; les mâles les plus petits semblaient être moins efficaces dans l'initiation des attaques sur les arbres, et les femelles les plus petites ont eu une fécondité réduite. Les durées de vol quotidiennes pendant la vie des mâles TK vierges étaient en moyenne deux fois plus longues que celles des mâles TN. Les durées de vol quotidiennes étaient très variables: en moyenne moins de 20 minutes, mais la plus longue a été de 173 mn. En moyennes les adultes TN et TK ont commencé à voler, et volaient en plus grand nombre, le premier et le second jour après l'émergence. Ensuite la fréquence d'adultes volants et le pourcentage de surviveants, ont graduellement diminué jusqu'à tomber à zéro le neuvième jour. Les mâles TN et TK avaient des vols quotidiens plus longs et volaient environ 1 jour de plus que les femelles. L'activité de vol accrue des mâles reflète leur besoin de trouver dans la nature des arbres convenables; les vols des femelles peuvent généralement être plus brefs, étant plus directement orientés comme une réponse aux phéromones mâles. Les voiliers ont vécu environ 2 fois plus longtemps que les non-voiliers. Parmi les voiliers TK et TN il y avait une corrélation positive étroite entre le poids du corps et la durée totale des vols. Il n'y en a qu'une faible corrélation entre cette durée totale des vols et la longévité, suggérant un faible coût physiologique du vol. L'influence de cette durée des vols et du prélèvement consécutif de lipides sur la fécondité n'a pas été examinée. L'initiation au vol chez les individus fécondés a été sérieusement retardée (maximum le sixième jour) par rapport aux vierges, ce qui suggère un dégénérescence des muscles du vol associée à la reproduction, suivie d'une régénération importante, comme cela a été signalé chez d'autres Scolytes. Ces résultats contribuent à notre compréhension des facteurs conditionnant le comportement de vol et d'autres aspects fondamentaux de la biologie des insectes des pins. Une telle connaissance est nécessaire au développement d'une politique efficace de protection.
    Notes: Abstract Rearing larvae of Ips calligraphus (Germar) (Coleoptera: Scolytidae) in bolts of typical slash pine, Pinus elliottii Engelm. var. elliottii, with ‘thin’ (TN; 0.5–1.5 mm) phloem (inner bark) relative to adult beetle body width significantly reduced body weight and lipid content of emerging adults compared with ‘thick’ (TK; 2.5–3.5 mm) phloem-reared adults. Unmated (pre-nuptial) TK beetles averaged 2-fold longer daily and life-time flight duration than TN beetles. Daily flights were highly variable, averaging 〈20 min (longest daily flight=173 min). TK and TN beetles initiated flight, and the greatest number flew, on the first or second day after emergence form their rearing bolt; % of beetles flying and survival gradually declined to zero by day 9. Males (both TK and TN) averaged 2.5 days of flight, ca. 1 day longer than females. Fliers lived ca. 2-fold longer than non-fliers. Among TK and TN fliers, significant but weak positive correlations occurred between body weight and lifetime flight duration. Poor correlation between lifetime flight duration and longevity suggests little physiological cost to flight, but effects on fecundity were not assessed. Flight by mated, egg-laying (post-nuptial) beetles was substantially delayed (peaking on day 6), suggesting degeneration and subsequent regeneration of flight muscles.
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  • 36
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    Entomologia experimentalis et applicata 43 (1987), S. 205-208 
    ISSN: 1570-7458
    Keywords: Coleoptera ; Chrysomelidae ; Diabrotica virgifera ; corn rootworms ; prehatch development ; posthatch development ; protandry
    Source: Springer Online Journal Archives 1860-2000
    Topics: Biology
    Description / Table of Contents: Résumé L'observation, au laboratoire, pendant une période d'éclosion de dix jours, des oeufs de D. v. virgifera LeConte, a montré que les oeufs mâles prédominent les deux premiers jours d'éclosion, que les oeufs des deux sexes, avec des fréquences 0,5/0,5, ont éclos les troisième et quatrième jours, et que les oeufs éclos du cinquième au dixième jour étaient presque tous femelles. Globalement, les oeufs femelles ont éclos en moyenne 2,9 jours plus tard que les oeufs mâles. De plus, la durée du développement post-embryonnaire des femelles a demandé 1,8 jour en plus. Une éclosion plus tardive et un développement post-embryonnaire plus long ont entrainé une émergence des femelles en moyenne 4,7 jours après les mâles. La période d'émergence des adultes s'est étalée sur 14 jours; les mâles ayant dominé pendant les 5 premiers jours et les femelles pendant les 9 derniers. Les mâles de D. v. virgifera semblent avoir évolué vers la protandrie en acquerant, tant une diapause post-embryonnaire que des stades de développements larvaire et nymphal plus brefs.
    Notes: Abstract Laboratory tests with eggs of Diabrotica virgifera virgifera LeConte showed that during a 10-day hatching period, hatch of male eggs predominated on the first and second days, eggs of mixed sex, with ca. 1:1 ratio, hatched on the third and fourth days, and eggs hatching from the fifth to the tenth days were nearly all female. Overall, female eggs hatched a mean of 2.9 days later than male eggs. Not only did female eggs hatch later, but the time for posthatch development to the adult stage was 1.8 days longer for females. The later egg hatch and longer posthatch development for females resulted in female adults emerging a mean of 4.7 days later than male adults. Total adult emergence lasted 14 days; of this, males predominated during the first 5 days, and females predominated during the last 9 days. Males of D. v. virgifera appear to have evolved protandry (the tendency for males to emerge before females) by developing both a postdiapause embryonic stage and a combined larval and pupal stage of shorter duration.
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  • 37
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    Entomologia experimentalis et applicata 44 (1987), S. 15-21 
    ISSN: 1570-7458
    Keywords: Callosobruchus maculatus ; Coleoptera ; Bruchidae ; intraspecific competition ; oviposition strategies ; resource exploitation ; vibrations
    Source: Springer Online Journal Archives 1860-2000
    Topics: Biology
    Description / Table of Contents: Résumé Lors de la compétition, les larves réagissent l'une par rapport à l'autre, même lorsque leurs galeries sont séparées. L'une est inhibée, tandis que l'autre se comporte comme si elle était seule. Le signal provoquant ces réactions, qui peut traverser du papier métallique, est dû vraisemblablement aux vibrations de mastication des larves; ces dernières perçoivent ces signaux tout au long de leur vie active. La larve la plus âgée ne l'emporte pas obligatoirement, ce qui signifie que le signal indique plus que l'âge. Les conditions expérimentales peuvent inverser les réponses des unes et des autres, bien que la larve la plus âgée puisse souvent mourir de ces conditions anormales de compétition. L'avantage potentiel associé à l'inhibition du futur perdant est mis en évidence en collant ensemble des graines. Quand la larve dominante se nymphose, la larve inhibée recommence à s'alimenter et achève son développement. En ayant eu son alimentation interrompue et en restant dans une galerie superficielle, la larve inhibée évite les affrontements et peut se développer lorsque la larve dominante meurt ou se nymphose, puisque la galerie de la larve inhibée n'avait pas été sectionnée. La stratégie de ponte réduit la fréquence de la compétition en uniformisant la distribution des oeufs; elle augmente les chances de survie des larves vaincues avec l'addition des oeufs sur les graines les plus grosses quand les disponibilités sont limitées. L'étude de l'évolution de ces adaptations a été possible puisque, comme on le sait, C. maculatus est génétiquement polymorphe pour les caractères déterminant le comportement de ponte des femelles et la compétition larvaire.
    Notes: Abstract Larvae of the bean weevil C. maculatus feeding in a single bean apparently respond to vibrations from each other's chewing: one larva feeds normally, the other is inhibited. If the burrows of the larvae intersect, the inhibited larva dies. If the dominant larva pupates or dies without the burrows intersecting, the inhibited larvae then feeds and matures if enough food remains. Since females add second eggs to the largest beans after most beans carry a single egg, competition is most common in the largest available beans, precisely where inhibited larvae can benefit from avoiding a contest.
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  • 38
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    Entomologia experimentalis et applicata 34 (1983), S. 124-126 
    ISSN: 1570-7458
    Keywords: Negret ; Melanic mutant ; X-linked mutation ; Flour Beetle ; Tribolium confusum ; Coleoptera
    Source: Springer Online Journal Archives 1860-2000
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  • 39
    ISSN: 1570-7458
    Keywords: Storage pests ; Coleoptera ; Bostrichidae ; Prostephanus truncatus ; (±)-1-methylbutyl (E)-2-methyl-2-pentenoate ; Rhyzopertha dominica ; (±)-1-methyl-butyl (E)-2,4-dimethyl-2-pentenoate ; Dominicalure ; Aggregation pheromone ; Monitoring
    Source: Springer Online Journal Archives 1860-2000
    Topics: Biology
    Description / Table of Contents: Résumé Les réponses de Prostephanus truncatus Horn (Coleoptera: Bostrichidae) à deux constituants de la phéromone d'agrégation de Rhyzopertha dominica Fabricius (Coleoptera: Bostrichidae), le (±)-1-méthylbutyl (E)-2-méthyl-2-penténoate et le (±)-1-méthylbutyl (E)-2,4-diméthyl-2-pentéoate, connus comme “Dominicalure 1” et “Dominicalure 2”, ont été étudiées au laboratoire et au champ. Auslaboratoire ces composés ont été essayés individuellement et en mélange 1:2. Une membrane de caoutchouc imprégnée de phéromone a été utilisée comme émetteur lent, et une courbe de réponse en fonction de la dose a été établie. P. truncatus répondait plus vigoureusement à la Dominicalure 2 seule. Tous ces traitements ont été comparés dans un essai aux champs en Tanzanie, dans lesquels des pièges en carton ondulé contenant des diffuseurs de phéromone étaient placés dans des entrepôts de maïs dans les fermes. La Dominicalure 1 et le mélange de 1 et 2 étaient tous deux efficaces pour piéger R. dominica. La Dominicalure 2 a piégé plus de P. truncatus que les autres traitements et était à peu près aussi efficace que le contrôle visuel pour détecter la présence de cet insecte dans les stocks. On peut envisager que la Dominicalure 2 pourrait servir de base à un programme pour lutter contre P. truncatus en Afrique de l'Est.
    Notes: Abstract Laboratory and field studies have been made of the responses of Prostephanus truncatus (Horn) to two components of the aggregation pheromone of Rhyzopertha dominica (Fabricius) — (±)-1-methylbutyl (E)-2-methyl-2-pentenoate and (±)-1-methylbutyl (E)-2,4-dimethyl-2-pentenoate, known as “Dominicalure 1” and “Dominicalure 2” respectively. In the laboratory, these compounds were tested individually and as a 1:2 mixture; P. truncatus responded most strongly to Dominicalure 2 alone. All three treatments were compared in a field trial in Tanzania to monitor both R. dominica and P. truncatus in farm stores. Dominicalure 1 or a mixture of 1 and 2 were both highly effective for trapping R. dominica. In contrast, Dominicalure 2 trapped more P. truncatus than the other treatments and was about as effective as visual inspection at demonstrating the presence of the beetle in stores. Dominicalure 2 could form the basis of a monitoring programme for P. truncatus in East Africa.
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  • 40
    ISSN: 1570-7458
    Keywords: Coleoptera ; Bruchidae ; diapause reproductrice ; inflorescence ; Vigna unguiculata ; activité sexuelle mâle ; ovogenèse ; ponte
    Source: Springer Online Journal Archives 1860-2000
    Topics: Biology
    Description / Table of Contents: Summary Bruchidius atrolineatus (Pic) is a widely distributed bruchid in the Sahelian zone which shows a reproductive diapause during the dry season and part of the rainy season. Diapausing females do not produce vitellogenin and their ovaries are reduced to the germarium. Spermatogenesis is very much reduced and male accessory glands are inactive. When these insects were placed in the presence of inflorescences of Vigna unguiculata which were renewed daily, the reproductive diapause of both males and females was interrupted after 15–20 days. Vitellogenesis occurred in the females and spermatogenesis increased in the males whilst their accessory glands became functional. When diapausing bruchids, found in stores of on V. unguiculata seeds during the dry season, were placed near the host plant's inflorescences, diapause was also terminated. In all cases, diapause was not interrupted when the insects were offered dry pods of V. unguiculata in a water-saturated atmosphere. The pollen, which is hardly eaten by this bruchid, did not seem to stimulate termination of diapause. Sensory stimulations derived from the flowers or/and nutritional factors may be the cause of the development of the reproductive organs. After termination of the diapause the males showed normal sexual activity whereas female fecundity was rather low, at least in our experimental conditions. This type of reproductive regulation allows this sahelian bruchid to resume its sexual activity when the host plant's flowers appear in the field at the end of the rainy season. Then the beetles lay their eggs on the pods as soon as the pods are developed.
    Notes: Abstract Bruchidius atrolineatus (Pic) présente en zone sahélienne une diapause reproductrice durant la saison sèche et une partie de la saison des pluies. Les femelles diapausantes ne produisent pas de vitellogénine et le germarium des ovarioles est seul développé. Chez les mâles la spermatogenèse est très ralentie et les glandes annexes sont inactives. Lorsque les insectes diapausants sont placés en présence d'inflorescences de Vigna unguiculata Walp, leurs organes reproducteurs deviennent fonctionnels après un temps de latence de 15 à 20 jours. Il n'y a par contre aucune levée de la diapause chez des bruches placées en présence de gousses sèches de V. unguiculata dans une atmosphère saturée. Des informations sensorielles issues des pièces florales ou (et) des facteurs nutritionnels sans doute liés a la consommation de nectar semblent être à l'origine de cette levée de la diapause. Le pollen fort peu consommé n'a par contre aucun rôle. Cette régulation du cycle reproducteur de B. atrolineatus par les inflorescences de V. unguiculata permet l'émission des oeufs dès que les gousses commencent à se former à la fin de la saison des pluies.
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  • 41
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    Entomologia experimentalis et applicata 41 (1986), S. 219-230 
    ISSN: 1570-7458
    Keywords: Coleoptera ; Scolytidae ; Ips typographus ; Y-tube olfactometer ; bioassay ; pheromone ; attack phase
    Source: Springer Online Journal Archives 1860-2000
    Topics: Biology
    Description / Table of Contents: Résumé Un olfactomètre à tube en Y, dont la description est donnée, a été utilisé pour examiner les réactions d'I. typographus L. par la marche à la présence de phéromones de congénères creusant des galeries dans des bûches d'Epicéa (Picea abies L.). Les insectes dans les bûches ont été répartis en 7 classes séquentielles, depuis l'élaboration de la chambre nuptiale par le mâle (phases 1–3), l'accouplement (4), et la ponte jusqu'à ce que les galeries de ponte aient 5 cm (5–7). Les mâles dans les phases précoces (1–2) étaient attractifs pour les 2 sexes dès 0,5 à 2,5 h après leur introduction, et ils le restaient pendant plus de 2 semaines. Les femelles qui se déplacent par la marche ont préféré nettement les bûches avec des mâles vierges à des bûches non habitées. De même elles ont préféré des bûches avec des mâles unis aux femelles à des bûches sans Ips. Ayant à choisir entre des bûches infestées par des mâles vierges ou expérimentés, les femelles ont préféré nettement les mâles vierges. Les mâle ont présenté une plus faible attraction aussi bien pour les bûches avec mâles vierges qu'avec mâles expérimentés, ils n'ont pas manifesté de préférence entre les 2. Les résultats sont interprétés comme des réponses adaptatives des 2 sexes aux variations dans la libération de phéromones par les insectes pendant les phases successives d'attaque et de colonisation de l'hôte.
    Notes: Abstract A Y-tube olfactometer is described which was used to assay the response of walking Ips typographus (L.) towards the pheromone from beetles excavating galleries in logs of Norway spruce [Picea abies (L.) Karst]. Beetles in the logs were categorized into seven sequential attack phases. Males in the early attack phases were attractive as early as 0.5 to 2.5 h after their introduction. These logs remained attractive for more than 2 weeks. Walking females strongly preferred logs with unmated males over uninfested logs and over logs containing males and females. They also preferred logs with males and females over uninfested logs. Responding males showed a weaker attraction than females to logs with unmated males. The results are interpreted as adaptive responses of the sexes to variation of pheromone release from beetles in the host during subsequent phases of attack and colonization.
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  • 42
    ISSN: 1570-7458
    Keywords: Aleochara bilineata ; Staphylinidae ; Coleoptera ; Delia radicum ; carbofuran ; diflubenzuron ; Dimilin ; Furadan ; insect growth regulator
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    Topics: Biology
    Description / Table of Contents: Résumé Lorsqu' appliqué dans des concentrations efficaces contre la mouche du chou Delia radicum L. (0.1, 0.01, 0.001% p/v dans de l'eau distillée), le Dimilin (diflubenzuron), un régulateur de croissance des insectes, n'a pas affecté l'éclosion des oeufs de Aleochara bilineata Gyllenhal, un staphylin prédateur et parasite. En application externe, à la plus forte concentration (0.1% p/v dans de l'eau distillée), cet inhibiteur de synthèse de la chitine s'est avéré non toxique pour les larves du premier stade, les stades larvaires qui se développent à l'intérieur du puparium de l'hôte, et les adultes. Le traitement au Dimilin n'a pas affecté la fertilité des staphylins adultes. Cependant, lorsque le diflubenzuron était dissous dans du diméthylsulfoxyde et appliqué sur l'exosquelette du puparium de l'hôte, l'émergence des adultes de A. bilineata était éliminée. L'insecticide conventionnel Furadan (carbofurane), à une concentration égale à la plus faible concentration de Dimilin utilisée (0.001% p/v dans de l'eau distillée), s'est avéré toxique à la fois pour les oeufs et pour les larves de A. bilineata.
    Notes: Abstract The insect growth regulator Dimilin®, common name: diflubenzuron, applied at concentrations effective against the cabbage maggot Delia radicum L., did not affect the hatching of eggs of the staphylinid predator and parasite, Aleochara bilineata Gyllenhal. Applied externally in distilled water, Dimilin was non-toxic to first instar larvae, to larval instars developing within host puparia, and to adults. When Dimilin was dissolved in dimethylsulfoxide, then applied to the exoskeleton of host puparia, emergence of A. bilineata adults was suppressed. The conventional insecticide Furadan, at a concentration (0.001% in distilled water) equal to the lowest concentration of Dimilin used, was toxic to both eggs and larvae of A. bilineata.
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  • 43
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    Entomologia experimentalis et applicata 46 (1988), S. 47-54 
    ISSN: 1570-7458
    Keywords: Coleoptera ; Curculionidae ; Sitophilus ; S. oryzae ; S. zeamais ; rice weevil ; maize weevil ; geographical strains ; digestion ; amylase ; diet ; barley ; corn ; maize ; rice ; wheat ; amylase inhibitors
    Source: Springer Online Journal Archives 1860-2000
    Topics: Biology
    Description / Table of Contents: Résumé La transformation de rang des valeur d'activité spécifique de l'α-amylase de 4 souches de S. oryzae et de 4 souches de S. zeamais montre que les niveaux les plus élevés de ces enzymes prédominantes s'observent chez les adultes nourris d'orge mondé ou de riz brun á grains longs. Des niveaux intermédiaires d'activité ont été obtenus chez les insectes élevés sur maïs jaune, et les niveaux les plus faibles chez ceux élevés sur blé. Bien que les extraits préparés à partir d'orge présentent une activité inhibitrice de deux isoamylases purifiées de S. oryzae, les niveaux des inhibiteurs naturels α-amylase de ces deux enzymes sont environ respectivement 2,2 et 6,1 fois plus concentrés dans le blé. L'ingestion de ces inhibiteurs d'amylase et la formation d'un complexe enzyme inactive/inhibiteur avec l'amylase secrétée antérieurement, peut rendre compte de la plus faible activité de l'amylase chez les charançons consommant du blé. Le niveau d'amylase de S. oryzae est 2 fois plus élevé que celui de S. zeamais pour toutes les souches élevées sur un régime donné. Des niveaux d'activité significativement différents ont été trouvés suivant les souches pour chacune des deux espèces. Puisque l'amylase est la principale hydrolase digestive de ces espèces, l'intensité de la modification des teneurs en amylase par la consommation de céréales peut indiquer leur adéquation comme hôtes potentiels.
    Notes: Abstract Rank transformation of specific activity values of α-amylase across four strains of Sitophilus oryzae (L.) and four strains of S. zeamais Motschulsky indicates that levels of these predominant enzymes are highest in adults feeding on hulled barley or long-grain brown rice. Intermediate activity levels are found in weevils feeding on yellow corn (maize) and lowest levels are found in wheat-fed weevils. Although extracts prepared from barley contain inhibitory activity against two purified isoamylases from S. oryzae, levels of the naturally-occurring α-amylase inhibitors against these two enzymes are about 2.2-fold and 6.1-fold, respectively, more concentrated in wheat. Ingestion of these amylase inhibitors and formation of an inactive enzyme:inhibitor complex with previously secreted amylase may account for the lower activity of amylase in weevils of both species feeding on wheat. Amylase levels across all strains feeding on a given diet are about 2-fold higher in S. oryzae than in S. zeamais. Significant differences in activity levels were also found between strains in both species. Since α-amylase is a predominant digestive hydrolase in these species, the degree to which cereal diets affect amylase levels may indicate their suitability as potential hosts.
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  • 44
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    Entomologia experimentalis et applicata 44 (1987), S. 53-58 
    ISSN: 1570-7458
    Keywords: Tomicus piniperda ; Coleoptera ; Scolytidae ; host recognition ; host volatiles ; attraction ; low vigor trees ; attacked trees
    Source: Springer Online Journal Archives 1860-2000
    Topics: Biology
    Description / Table of Contents: Zusammenfassung Der Anflug von Tomicus piniperda (L.) (Coleoptera: Scolytidae) an Kiefern in schlechtem oder besserem Gesundheitszustand, mit oder ohne vorherigen Befall, wurde mit Hilfe von Leimfallen untersucht. An Bäumen in schlechtem Zustand wurden etwas mehr Käfer gefangen als an Bäumen in besserem Gesundheitszustand. Das deutet auf Unterschiede in Geruchsreizen zwischen den beiden Klassen des Baumzustands hin. An Kiefern, die von T. piniperda befallen waren oder simulierte Einbohrungen (von Hand gebohrte Löcher) hatten, wurden viel mehr Käfer gefangen als an Kontrollbäumen ohne oder mit sehr geringem Befall. Der starke Anflug von Käfern an befallene Bäume wird gedeutet als Reaktion auf Duftstoffe des Wirts, die aus den Borkenkäfergängen abgegeben werden.
    Notes: Abstract The attraction of Tomicus piniperda (L.) (Coleoptera: Scolytidae) to Scots pine trees of low and higher vigor with and without previous attacks was monitored with sticky traps. Somewhat higher numbers of beetles were caught on low vigor trees than on trees of higher vigor, indicating differences in olfactory stimuly between the two classes of trees. Many more beetles were caught on trees attacked by T. piniperda and on trees with simulated bark beetle galleries (manually drilled holes) than on control trees with no or only a few attacks. The strong attraction of beetles to attacked trees is attributed to the beetles responding to host volatiles released from the galleries.
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  • 45
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    Entomologia experimentalis et applicata 48 (1988), S. 157-163 
    ISSN: 1570-7458
    Keywords: sweet potato weevil ; Cylas formicarius elegantulus ; Coleoptera ; Curculionidae ; sweet potato ; Ipomoea batatas ; feeding ; host-plant preference ; leaf surface chemistry
    Source: Springer Online Journal Archives 1860-2000
    Topics: Biology
    Description / Table of Contents: Résumé L'étude a porté sur la consommation pendant 12 h, en boîtes de Pétri de diamètre 9 cm, de rondelles de 2 cm de diamètre de feuilles de 4 cultivars,—Centennial, Jewel, Resisto, Regal—, d'I. batatas par C. formicarius elegantulus. Les charançons ont consommé le long des nervures, préférant la face inférieure à la face supérieure des feuilles. Un index de consommation a été calculé en fonction de la longueur de nervure ayant servi à la consommation, rapportée à la longueur totale des nervures de la surface exposée. Les niveaux de consommation des mâles et des femelles étaient semblables. En présence de choix binaires, le cultivar Centennial a été le plus consommé, et le cultivar Resisto, le moins, par les femelles. De telles préférences n'ont pas été observées en l'absence de choix. La composition chimique de la surface de la feuille a été analysée par chromatographie en phase gazeuse. 8 pics principaux identiques ont été observés chez les 4 cultivars, mais ils avaient différentes hauteurs.
    Notes: Abstract A bioassay was developed to quantify the feeding of adult sweet potato weevils, Cylas formicarius elegantulus (Summers) (Coleoptera; Curculionidae) on the foliage of four cultivars (Centennial, Jewel, Resisto and Regal) of sweet potato (Ipomoea batatas (L.) Lam.) (Convolvulaceae). Weevils fed along the leaf veins, preferring the lower to the upper leaf surface. Males and females had similar levels of feeding. Different levels of feeding by female weevils were observed between cultivars in dual-choice bioassays with Centennial, a susceptible cultivar in field-plot experiments, being most preferred and Resisto least preferred. However, these feeding differences were not observed in no-choice bioassays. Little difference was observed in the leaf surface chemistry of the four cultivars.
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  • 46
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    Applied physics 45 (1988), S. 279-284 
    ISSN: 1432-0649
    Keywords: 07.65 ; 33 ; 42.55 ; 82.50
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    Topics: Physics
    Notes: Abstract The photophysical properties such as singlet absorption and fluorescence spectra, the fluorescence quantum yield and fluorescence decay time as well as the laser performance data such as the tuning range, the conversion efficiency, and the photochemical stability of 12 sterically hinderedp-quaterphenyls have been measured in ethanol and/or dioxane at room temperature. The sterically hinderedp-quaterphenyls exhibit shorter laser dye emissions in the 330–380 nm range than the parent compoundp-quaterphenyl. The conversion efficiencies of the sterically hinderedp-quaterphenyls range between 1 and 21%. The photochemical stability of the sterically hinderedp-quaterphenyls is by a factor of 10 to 20 better in dioxane than in ethanol. 2-Methyl-5-tert. butyl-p-quaterphenyl and 2,5,2‴,5‴-tetramethyl-p-quaterphenyl are among the most stable UV laser dyes known today.
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  • 47
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    Applied physics 33 (1984), S. 115-131 
    ISSN: 1432-0649
    Keywords: 02.20 ; 42.55 ; 42.60D
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    Topics: Physics
    Notes: Abstract This study puts forward the concept of helical distributed feedback (DFB) lasers. The basic features of this new type of laser are derived by group theoretical considerations on cylindrical, circular linear periodic, and helical waveguide and laser structures. It is demonstrated that not only linear periodic structures but also helical structures show Bragg and DFB effects. Microwave and far-infrared experiments on passive helical metal waveguides reveal Bragg resonances in transmission. These results initiated the first experimental realization of a helical DFB gas laser, i.e. an optically pumped 496μm CH3F laser with a helical metal waveguide of a pitch close to 250μm. This helical DFB laser shows higher-mode selectivity than the corresponding linear DFB laser. Finally, we show that the concept of helical DFB also applies to dye lasers with internal DFB incorporated by a mixture of the dye with a cholesteric liquid crystal.
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  • 48
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    Applied physics 34 (1984), S. 17-21 
    ISSN: 1432-0649
    Keywords: 42.55
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    Topics: Physics
    Notes: Abstract Twenty-four new optically pumped submillimetre laser lines have been observed when CH3OH is excited using a13C18O2 pump laser. Four of these lines have been assigned to transitions involving the CO stretching band. In addition to these lines, a further six new lines have been observed when pumping with12C18O2 and13C16O2 lasers. One of these lines has been assigned to a transition involving the CO stretching band. The observation of infrared-infrared double resonance signals in CH3OH has allowed the prediction of a further six laser lines which should be excited using a13C18O2 pump laser.
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  • 49
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    Applied physics 34 (1984), S. 221-228 
    ISSN: 1432-0649
    Keywords: 42.55 ; 41
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    Topics: Physics
    Notes: Abstract The conditions under which a cooperative emission from different friges occurs in the scattering between a relativistic electron beam and two interfering laser beams are discussed. In particular, the conditions to have an electron grating are discussed.
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  • 50
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    Applied physics 49 (1989), S. 29-32 
    ISSN: 1432-0649
    Keywords: 42.55 ; 42.60B
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    Notes: Abstract Design and characteristics of an “external cavity single mode GaAs diode laser” are described which allow continuous wavelength tuning over 50 GHz without mode hops. Tuning is achieved by synchronous tilting of both a thin solid etalon and a Brewster plate inside the laser resonator. Stabilizing the laser frequency to an external Fabry-Perot interferometer yields a frequency stability of ≦1 MHz at output powers up to 20 m W.
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  • 51
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    Applied physics 35 (1984), S. 77-82 
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    Keywords: 42.55 ; 42.65
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    Notes: Abstract The coexistence of bistability and repetitive passive Q-switching of a CO2 laser with a gaseous saturable absorber has been investigated experimentally. With CH3F as the saturable absorber bistability has been observed simultaneously with passive Q-switching, whereas with CH3OH either one of these phenomena can only exist, as demonstrated for the first time. The measured features of both systems can be explained qualitatively by rate-equation theory.
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  • 52
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    Applied physics 35 (1984), S. 127-129 
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    Notes: Abstract Strong submillimetre laser action has been obtained on five lines of a new laser gas, formaldoxime. Several new emission lines have also been produced by isotopic CO2 laser pumping of14NH3 and15NH3. One of these lines at 102.9 μm is a rotation-inversion transition in the 2v 2 state, and is the first example of cw laser action in such a highly excited state.
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  • 53
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    Applied physics 37 (1985), S. 205-207 
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    Keywords: 42.55 ; 42.60
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    Notes: Abstract Efficient wavelength tuning from 446 to 524 nm with a minimum spectral linewidth of 1 nm was demonstrated for an electron beam pumped XeF(C→A) laser. Energy densities of 0.1 J/l were obtained for an optimized Ar/Kr/Xe/F2/NF3 mixture.
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  • 54
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    Applied physics 37 (1985), S. 209-211 
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    Notes: Abstract Thirteen new submillimetre emission lines have been observed when pumping CH3OD using isotopic CO2 lasers, and fourteen when pumping CD3OD. Three isotopic CO2 lasers were used12C16O2,12C18O2, and13C16O2. The new lines were observed in a Fabry-Perot resonator. The wavelength ranges observed were from 55 to 320 μm for CH3OD and from 66 to 531 μm for CD3OD. The polarisation of the submillimetre laser lines relative to the CO2 pump line has also been determined.
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  • 55
    ISSN: 1432-0649
    Keywords: 33 ; 82.50 ; 42.55
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    Topics: Physics
    Notes: Abstract We measured the photoionization cross-sections of anthracene, 1,2-benzanthracene,p-terphenyl, and 2,5-diphenylfuran molecules excited to the singlet and triplet electronic states intermediate in the stepwise two-photon ionization process at 266 nm (all compounds) and at 355, 391 and 417 nm (anthracene).
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  • 56
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    Applied physics 40 (1986), S. 153-155 
    ISSN: 1432-0649
    Keywords: 42.60 ; 42.55
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    Notes: Abstract For a (0.5–0.6)m long He−Ne laser tube, single longitudinal mode 632.8 nm generation is obtained, using a higher gas-mixture pressure and application of an axial magnetic field. An efficient and very simple mode selection is obtained by gas-mixture pressure increase only. A multimode power to single-mode power conversion coefficientk=0.75 is obtained by increasing the tube pressure. A further increase tok=0.85 is possible with optimum magnetic field and gas pressure.
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  • 57
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    Applied physics 41 (1986), S. 125-129 
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    Notes: Abstract This paper reports the observation and analysis of several different opticalpumping and energy-transfer processes for generating stimulated radiation, including equal or unequal frequency two-step Na2−K and K2−K hybrid resonance. A series of infrared stimulated and cascade stimulated lines by the transitions in atomic potassium were detected.
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  • 58
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    Applied physics 28 (1982), S. 373-381 
    ISSN: 1432-0649
    Keywords: 42.55 ; 42.80 ; 52
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    Notes: Abstract We investigated noise and fluctuations of the output power of cataphoretic HeSe+ lasers in positive column plasma. Direct coupling of laser output power noise and fluctuations of the local population inversion was found. An investigation of the positive column plasma showed moving striations being responsible for the gain fluctuations. Whereas the local plasma properties are dominated by high frequency striations in the 100 kHz range, integrated quantities such as laser gain per pass are most strongly influenced by low-frequency waves with a continuous noise spectrum below 200 kHz. External modulation of the discharge voltage or current at a frequency near thehf striations reduces laser noise and increases laser output power.
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  • 59
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    Keywords: 32 ; 42.55
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    Notes: Abstract Optical absorption,S 1 lifetime, and photostability are investigated for a series of heptamethine ir dyes and related to chemical structure. The high photostability of several dyes and the large range ofS 1 lifetimes make these dyes very interesting for ir dye lasers and for ir mode-locked laser systems.
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  • 60
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    Applied physics 29 (1982), S. 13-14 
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    Keywords: 42.55
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    Notes: Abstract Intense far-infrared laser action is reported for carbonyl fluoride and vinyl fluoride. Eleven new lines with wavelengths between 339 μm≦λ≦538 μm were obtained by optically pumping carbonyl fluoride with numerous lines of the 10.4 μm band of a cw CO2 laser. Twenty-three lines with wavelengths in the range 172 μm≦λ≦783 μm were detected when pumping the recently discovered efficient FIR laser molecule vinyl fluoride. In addition, three very weak new lines were found using 1.1-difluoroethylen.
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    Applied physics 29 (1982), S. 263-267 
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    Notes: Abstract The duration, shape, and background intensity level of pulses of a passively modelocked Nd-glass laser are determined by noncollinear phase-matched four-photon frequency mixing of time-separated fundamental and second-harmonic pulses in a KI crystal. The pulse shape is found to be slightly asymmetric with slower trailing than rising parts. The background intensity level before and behind the main pulse is about 5¢10−6 the peak pulse intensity.
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    Applied physics 30 (1983), S. 1-4 
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    Notes: Abstract Twenty FIR laser lines with wavelengths between 146 and 2000 μm have been observed from deuterated formyl fluoride (DCOF) optically pumped with isotopic CO2 lasers. Tunable diode laser measurements on thev 4 band of DCOF were combined with earlier high precision spectroscopic data on thev 3 andv 4 bands, and enabled identification of the transitions responsible for 9 of the new FIR lines.
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    Applied physics 30 (1983), S. 135-142 
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    Notes: Abstract An analysis of cw synchronously pumped dye lasers is presented. Under the assumption that the cavity (tuning element) bandwidth is much wider than the bandwidth of the transform limited pulses generated, the pulse forming dynamics is rigorously treated. It is shown that for a finite mismatch between the lengths of the dye and the pump lasers, a steady-state pulse develops in the dye laser cavity with a conserved pulseshape. The characteristics (energy, shape, peak power, duration) of these pulses of ultimate width are quantitatively determined as a function of cavity mismatch. An analytical solution for the pulse envelope is determined, which yieldsI(t)∝Sech2(t/t p ) to a good approximation.
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  • 64
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    Applied physics 32 (1983), S. 75-78 
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    Notes: Abstract Multiphoton absorption (MPA) of the CO2 laser 9 μmR(30) line (pulse width 60 ns, FWHM) by NH3 and NH3/N2 mixtures was studied as a function of gas composition, pressure and laser fluence (Φ). MPA occurs for Φ smaller than those that have been used for optically pumped NH3/N2 lasers; consequently a simple two-level absorption model will not adequately describe laser action in these systems. The photon energy deposited in NH3/N2 mixtures can be calculated from the MPA cross-section and the fluence dependence of the illumination geometry. An examination of the efficiency of conversion of this absorbed energy to the reported radiant energy of optically pumped NH3/N2 lasers shows an optimum value which depends on pressure, and gas composition.
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    Applied physics 32 (1983), S. 105-111 
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    Notes: Abstract The effects of H2, He, and N2 buffer gases on the efficiency of the cw 12.08 μm NH3 Raman laser are studied experimentally. The laser output power is increased by nearly 60% with the addition of H2 or He, which we essentially attribute to the high thermal conductivity of these buffer gases. In the optimum conditions (NH3/H2:1/1 mixture with 0.35 Torr partial pressure of NH3) 3.3 W output power at 12.08 μm is obtained which corresponds to 11% power conversion efficiency.
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  • 66
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    Applied physics 32 (1983), S. 127-135 
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    Notes: Abstract A cw uv copper hollow cathode laser is described, which could be operated for a longer time duration with an output power of 7 mW in the 260 nm region. A double-cathode configuration with a protection for the mirrors from metal-vapour deposition is presented. Characteristics of the laser output power, the spontaneous emission, and the ion densities in the negative glow were measured as depending on the discharge current, the neon gas pressure, and the size of the cathode slit. The observed saturation of the laser output power at high discharge current (1 A/cm2) and the optimum slot size are discussed.
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    Applied physics 33 (1984), S. 23-27 
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    Notes: Abstract For the first time stable cw output of a FIR-CO2 hybrid laser has been achieved at wavelengths shorter than 300 μm. Due to the saturable absorber characteristic of the FIR laser gas, cw or pulsed emission is observed on both, the CO2 and the FIR laser output, depending on the operating conditions. Results are reported on different resonant lines in CH3OH and the 67 μm Raman line in NH3. The good efficiency of this laser is also demonstrated by the excitation of two new emission lines in CH3OH, namely 49 and 56 μm, pumped by 9R(22) and 9R(24), respectively.
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    Applied physics 34 (1984), S. 83-86 
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    Notes: Abstract An XeF pumped vapor phase POPOP dye laser with a pulse duration of 300 ns was obtained when trans-stilbene was used as triplet quencher. An energy conversion efficiency of 7,5% with a peak power efficiency of 12% was measured.
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    Applied physics 34 (1984), S. 175-177 
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    Notes: Abstract 47 new cw far-infrared laser lines with wavelenths between 453 and 2356 μm have been obtained by optically pumping vinyl bromide (C2H3Br) by a CO2 laser. A significant portion of these lines has wavelengths longer than 750 μm.
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    Applied physics 35 (1984), S. 163-166 
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    Notes: Abstract We present an analytical expression for the small-signal gain of a Free Electron Laser (FEL) in the presence of a Gaussian mode. To describe the electron beam evolution we use the one-dimensional (1-d) Vlasov equation. Our perturbation result, valid for small values of the parameterq (length of the undulatorL divided by the Rayleigh rangeZ R), can be extrapolated to values ofq≈4÷5.
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    Applied physics 36 (1985), S. 149-153 
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    Notes: Abstract We observed and compared the opto-voltaic signals in CO and CO2 lasers. The signals are obtained capacitively from the water cooling jacket as a low voltage source not influencing the current circuit. We observed from measurement that the output power and the so-called optovoltaic input power have a distinct relationship depending on laser current and cavity parameters. It will be shown that opto-voltaic detection is a very sensitive method especially for CO lasers.
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    Applied physics 37 (1985), S. 7-9 
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    Notes: Abstract Rhodamine 6G-Cresyl violet dye mixtures are synchronously pumped to obtain double mode-locking. Subpicosecond pulses are obtained at two wavelengths in an experimental setup that is easy to implement into existing conventional synchronously pumped systems. In addition, the excitation mechanisms of the secondary dye are discussed and evidence for resonant energy transfer is presented.
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    Applied physics 37 (1985), S. 35-39 
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    Notes: Abstract In this paper we describe a simple and inexpensive Distributed Feedback Dye Laser (DFDL) system for picosecond pulse generation. This system consists of an oscillator-amplifier DFDL, either in the grating or in the prism configuration: both stages are pumped by a single TEA nitrogen laser with improved beam quality. Single pulses having duration of 26 ps are obtained at a frequency up to 100Hz; the overall pulse-to-pulse stability is, at the maximum frequency, of about 25%. This system is particularly well-suited for time-resolved fluorescence microscopy studies where short tunable laser pulses of low energy are required.
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    Applied physics 37 (1985), S. 229-232 
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    Notes: Abstract In this letter paper we analyse the effect of electron-beam qualities (namely, energy spread and emittances) on both spontaneous emission and gain of an Optical Klystron (OK). We use the relationship between average current and normalized emittances, typical of the accelerating machines without radiative damping, to evaluate the optimum operating parameters.
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    Applied physics 38 (1985), S. 165-169 
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    Notes: Abstract Conditions for the operation of a Tl photodissociation laser, in view of power optimization, have been determined. A crucial parameter is found to be quenching of the upper laser level. A value for the quenching cross-section of the 72 S 1/2 Tl state by the TlI molecules of 2×10−14 cm2 has been measured.
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    Applied physics 38 (1985), S. 191-197 
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    Notes: Abstract Laser dyes which are commonly used in pulsed laser pumped dye laser (PLPDL) systems have been investigated. It is shown that photoquenching plays an important role in the pumping process of all laser dyes, determining the efficiency of the PLPDL. Molecular parameters, such as absorption cross sections at various pumping wavelengths and fluorescence lifetimes of theS n (n〉1) excited electronic states of laser dyes, have been determined utilizing the photoquenching technique.
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    Applied physics 39 (1986), S. 201-217 
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    Notes: Abstract An experimental and theoretical investigation of the fluctuations of the pulses from continuous-wave mode-locked lasers is presented. It is shown that these fluctuations can be detected and quantitatively characterized from measurements of the power spectrum of the light intensity. Such power spectra can be measured with great accuracy by shining the laser output on a suitable photodetector and by processing the detector signal with the use of an electronic spectrum analyzer. Different types of noise such as fluctuations of the pulse energy, pulse repetition time, and pulse duration, can be readily recognized from their characteristic spectral signature. Experimental results of noise measurements are presented for a synchronously mode-locked dye laser pumped by an acousto-optically mode-locked argon ion laser, and also for a colliding pulse passively mode-locked dye laser.
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    Applied physics 41 (1986), S. 31-37 
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    Notes: Abstract Increasing the preionization electron density is found to be an effective method for improving the output performance of discharge-pumped excimer lasers at high gas pressures when the power-supply voltage becomes a limiting factor. In a small volume (2 cm3), x-ray preionized discharge, orders of magnitude improvement in XeCl laser power output (up to 400 kW) and pulse energy (up to 26 mJ) over previously reported results have been found possible using this method. Modifications to the low energy x-ray source and discharge system leading to these improvements are described. Various laser output characteristics are also presented and discussed.
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    Applied physics 41 (1986), S. 53-55 
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    Notes: Abstract The first passive mode locking of the continuous wave (cw) DCM dye laser is reported. Subpicosecond pulses as short as 0.68 ps were obtained over the spectral region from 655 to 673 nm from a simple linear cavity with no dispersion optimisation. The dye 1,3′ Diethyl 4,2′ quinolythiacarbocyanine iodide (DQTCI) was used as the saturable absorber.
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    Applied physics 41 (1986), S. 179-181 
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    Notes: Abstract Far-infrared laser action has been demonstrated in three previously unknown laser media. The substances used were: propargyl fluoride, 15-N cyanogen fluoride, and hydroxylamine. Assignments of the molecular transitions giving rise to the observed laser lines were made for the latter two compounds. New FIR laser lines were also observed with two substances, vinyl chloride and vinyl fluoride, which were already known as laser media by pumping with isotopic CO2 and N2O laser lines. The wavelengths of a total of 26 new FIR laser lines were determined together with the threshold pump power and an indication of the relative line strengths.
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    Applied physics 41 (1986), S. 231-234 
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    Notes: Abstract We discuss simple criteria which allow the determination of both an optimum drift strength and total length, for the optical klystron operation. The analysis of the gain reduction factors also includes the finite microbunch length. We extend the discussion to harmonic generation, where we also find an optimum for the input power.
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    Applied physics 43 (1987), S. 139-153 
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    Notes: Abstract A systematic description is developed for the dynamical behavior of a multi-mode unidirectional ring laser under modulation of the population inversion in a homogeneously broadened active medium. The modulation frequency is chosen to be close to the longitudinal mode spacing in the cavity. We report a rigorous and extensive numerical analysis of this system by choosing the dc component of the population inversion, the modulation amplitude and the detuning of the modulation frequency as control parameters for both cases of good and bad cavities. In the good cavity, this system exhibits two characteristic transitions toward the conventional mode-locked pulse oscillation as the modulation amplitude increases: the first transition to the region of the ordered amplitude and disordered phase of the electric field, and the second one to the ordinary mode-locking in which both the amplitude and the phase are ordered. In the bad cavity, two kinds of chaos are observed: the Lorenz-type chaos in the region of weak modulation and strong population inversion and the quasi-periodic chaos in the region of strong modulation and intermediate population inversion. The dimensionality of chaotic behaviors is also tested to reveal mechanisms of instability. The coherent and incoherent properties of emitted light at each region are clarified, too.
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  • 83
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    Notes: Abstract Injection phase locking of a powerful CO2 waveguide laser with a stable singlefrequency master oscillator is described. The locking range is experimentally investigated versus both injected signal frequency and slave cavity length. A locking tunability up to ±180 MHz from CO2 10P(20) line center has been achieved. Experimental results are in excellent agreement with the theoretical development exposed in the preceeding paper.
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    Applied physics 44 (1987), S. 111-117 
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    Notes: Abstract The CD3OH molecule has been investigated for new far-infrared laser lines by optically pumping with a cw waveguide CO2 laser. The increased tunability (300 MHz) with respect to a conventional CO2 laser permits to pump many new CD3OH lines. As a consequence 108 new laser lines have been discovered, ranging from 42.9 to 1155 μm in wavelength. On some lines the effect of an electric Stark field has been investigated demonstrating a laser frequency tuning. The total number of known FIR laser lines from CD3OH is increased to about 340 making this molecule the most prolific together with CH3OH.
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    Applied physics 47 (1988), S. 149-157 
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    Notes: Abstract We report the successful operation of a novel automatic impedance matching technique (AIMing) and observations of the opto-Hertzian effect. The AIMing system is capable of maintaining efficient RF power delivery to a CO2 waveguide laser over a wide range of operating conditions. The opto-Hertzian signal, produced by circulating laser power fluctuations and detected in the RF reflected power, has some interesting properties and may be used for laser frequency stabilisation.
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    Applied physics 49 (1989), S. 377-381 
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    Notes: Abstract We have studied the Doppler-broadened 11.76 μm 15NH3 emission line optically pumped in a ring resonator by a cw CO2 laser operating on the 10R(42) line. In the pure ammonia, even if the pumping occurs inside the Doppler width, the two-photon Raman process seems to be responsible for the laser emission. Both in the pure 15NH3 and in the 15NH3, N2, and He mixture we demonstrate the possibility of obtaining a unidirectional laser amplifier.
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    Applied physics 26 (1981), S. 161-167 
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    Notes: Abstract A new magnetic discharge stabilization technique for coaxial laser systems is described. The approach utilizes crosses electric and magnetic fields to create and maintain a large and rapidly rotating plasma volume which does not experience glow-to-arc transitions. Very high cw specific discharge power loadings have been achieved even without the benefit of external gas cooling or circulation. Performance is insensitive to gas composition and pressure such that high power coaxial discharges have been run in CO2 laser gas mixtures up to several hundred torr. Stable cw discharges have also been obtained in mixtures containing several torr of SF6. The technique appears to be readily scalable to give very large excited volumes in systems with comparatively small overall physical dimensions.
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    Applied physics 32 (1983), S. 83-84 
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    Notes: Abstract A population inversion between the 62 P 3/2 and 62 P 1/2 state of thallium has been achieved for the first time by incoherent photodissociation of TII. This is accomplished by using wall-ablating flashlamps of short risetime and appropriate light filtering. The inversion lasts about 4 μs and is terminated by quenching collisions.
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    Applied physics 32 (1983), S. 193-198 
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    Notes: Abstract The vibrational relaxation time constant for theB v=0 vibrational level of XeCl* has been investigated by observing the coupling between theB v=1 andB v=0 vibrational levels under saturated lasing conditions. Based on this observation, estimates of the expected extraction efficiency from theB-state have been made.
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    Applied physics 36 (1985), S. 213-216 
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    Notes: Abstract The relaxation of the optically excited Ag−-center in KI is investigated by measuring the risetime of the spontaneous emission from the relaxed excited state. The energy and number of phonons created in the relaxation process are determined.
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    Applied physics 37 (1985), S. 87-91 
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    Notes: Abstract The performance of a continuous-wave (cw) CO flame chemical laser (FCL) of the CS2/O2/CO2 type is presented. The laser gives up to 0.7 W cw output power on a number ofP v (J) lines corresponding to 11→10, ..., 7→6 vibrational bands of CO molecule. The measured values of chemical efficiency based on the reaction O+CS→CO*(v)+S and the specific power are 0.1% and 0.7J/g, respectively. The spectral composition of the CO FCL of the CS2/O2/CO2 type shows lasing in the region from 5.194 to 5.573 μm. All experimental measurements are conducted with a nondispersive optical cavity.
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    Applied physics 33 (1984), S. 9-16 
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    Notes: Abstract We derive the most general equations of motion for the electrons and the electromagnetic field in a free-electron laser including the effects of diffraction and pulse propagation. The field evolution is expressed in terms of the amplitudes and phases of a complete set of transverse modes. The analytic solution is given in the small-signal regime, where the theory is shown to be in excellent agreement with a recent experiment at Orsay.
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  • 93
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    Notes: Abstract Experiments on pressure dependence of a CF4 laser have been carried out to elucidate dynamic characteristics of CF4 molecules pumped by CO2 lasers. The results are followed by a model calculation which characterizes collisional quenching of the energy levels related to the stimulated emission. The enhancement of the laser output induced by buffer-gas addition, which was found under specific conditions, is discussed in relation to the competition between laser and superfluorescent emissions.
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    Notes: Abstract Experiments on homogeneous initiation of pulsed avalanche discharges in typical XeCl laser mixtures show that the x-ray preionization pulse remains effective after a time delay of the order of 20 μs even at very high gas pressures (∼15 atm). Detailed kinetics analyses indicate that dissociative attachment of HCl is relatively slow during and after the preionization period so that the long effective delay time cannot be attributed to the storage effect of Cl− ions. Instead, the observed phenomenon can be attributed to the long survival time of the free electrons due to relatively slow diffusion and electron-ion recombination. Some problems arising from quantitative interpretation of the experimental results are also noted and discussed.
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    Applied physics 38 (1985), S. 185-189 
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    Notes: Abstract A high-power, line-tunable NH3 laser pumped by a TEA CO2 laser has been developed for application to laser isotope separation of tritium. Laser lines from15NH3 are newly observed in a range from 11.24 to 13.23 μm. The performance of an15NH3 laser is compared to that of an14NH3 laser.
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    Applied physics 43 (1987), S. 203-208 
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    Notes: Abstract A theory of cw injection phase locking in homogeneously broadened media is investigated using density matrix formalism to derive the interactions of three coherent fields with a two levels system. This powerful formalism leads to analytical expressions of the complex gain for each wave propagating inside the amplifier medium. Studies of the minimum signal intensity for single-frequency operation and power output are related.
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    Applied physics 44 (1987), S. 67-69 
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    Notes: Abstract We have found twelve new FIR laser lines in12CH3OH and thirty three in13CH3OH. Both molecules were pumped by a regular cw CO2 laser. We have also assigned 2013CH3OH laser lines to specific rotational energy levels in the excited C-O stretchhindered rotation combined states
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    Applied physics 26 (1981), S. 73-76 
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    Notes: Abstract A liquid nitrogen cooled cw CO-Laser is described, with which laser action up to 8.18 μm (v=36→35) has been achieved.
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    Springer
    Applied physics 26 (1981), S. 141-146 
    ISSN: 1432-0649
    Keywords: 42.55
    Source: Springer Online Journal Archives 1860-2000
    Topics: Physics
    Notes: Abstract We have designed and tested a pulsed single-mode dye laser for spectroscopy experiments. The dye laser is pumped by a 6 kHz copper vapor laser to produce up to 230 mW average power at over 5% efficiency in a nearly diffraction limited beam. The dye laser pulse closely resembles the 30 ns pump pulse. Using an electronic servo loop, the 60 MHz wide line can be scanned, without mode hopping, through the 16 GHz permitted by the travel on the piezo driven mirror mount.
    Type of Medium: Electronic Resource
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    ISSN: 1432-0649
    Keywords: 42.55
    Source: Springer Online Journal Archives 1860-2000
    Topics: Physics
    Type of Medium: Electronic Resource
    Location Call Number Expected Availability
    BibTip Others were also interested in ...
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