ALBERT

All Library Books, journals and Electronic Records Telegrafenberg

feed icon rss

Your email was sent successfully. Check your inbox.

An error occurred while sending the email. Please try again.

Proceed reservation?

Export
  • 1
    ISSN: 1423-0445
    Keywords: competition ; inhibition ; sex-ratio ; mass-at-tack model ; ipsdienol ; E-myrcenol ; cis-verbenol ; 2-methyl-3-buten-2-ol ; Coleoptera ; Scolytidae
    Source: Springer Online Journal Archives 1860-2000
    Topics: Biology
    Notes: Summary Ips duplicatus withI. typographus co-inhabiting Norway spruce (Picea abies (L.) Karst.) would benefit from a pheromone blend distinct from that of the larger competitorI. typographus. GC-MS analysis showed thatI. duplicatus males feeding in the host produced ipsdienol (Id),cis-verbenol (cV),trans-verbenol (tV), myrtenol (Mt), andE-myrcenol (EM) and traces of 2-methyl-3-buten-2-ol (MB).I. duplicatus produced Id in approximately racemic form (48.9-54.5% (+)-(S)-isomer). The amounts of Id and EM released over a 9 day period had a maximum of 250 and 5 ng/h/male, respectively, on day 2. Exposure ofI. duplicatus males to myrcene and α-pinene resulted in the production of small amounts of Id, cV, tV, Mt, andtrans-pinocarveol, but not of EM. In laboratory bioassays with walking beetles, the pheromone component Id alone was weakly attractive while EM was inactive, but in binary combination with Id strongly synergized attraction. A combination of EM and Id at a release rate equivalent to 100–200 males was more attractive in the field than 70 unmated males in a spruce log. The addition of myrcene ( a suggested pheromone precursor of Id) to Id did not enhance trap caches, while addition of EM increased catches 〉 10-fold. Subtracting EM from a blend of Id, EM, cV and MB drastically reduced trap catches while subtraction of cV or MB or both had no significant effect. Addition of EM over a wide concentration range to the synthetic pheromone ofI. typographus did not reduce the attraction of females of this species in the laboratory. A two-species pheromone interaction field test releasingI. typographus pheromone components (MB + cV) at 10–1000 male equivalents (ME) andI. duplicatus pheromone (Id + EM) at 0, 10–1000 ME in all possible combinations showed both positive intraspecific dose-response effects and an interspecific inhibition. Higher release rates of EM appeared to inhibitI. typographus, especially males. In a tree colonization model, the response of the two competing species to their respective pheromones show a good separation during the mass-attack with a small initial cross-attraction. It remains to be shown whether either of the two pheromone systems have in fact evolved in the present sympatry, or if they are an incidental effect of ancestry of these phylogenetically distantIps.
    Type of Medium: Electronic Resource
    Location Call Number Expected Availability
    BibTip Others were also interested in ...
  • 2
    ISSN: 1573-1561
    Keywords: Synergism ; aggregation pheromone ; Pityogenes chalcographus ; Coleoptera ; Scolytidae ; chalcogran ; methyl (2E,4Z)-2,4-decadienoate ; enantiomers ; isomers ; stereoisomers ; synthesis ; bioassay ; structure-activity
    Source: Springer Online Journal Archives 1860-2000
    Topics: Biology , Chemistry and Pharmacology
    Notes: Abstract Syntheses of all four Stereoisomers (2S,5S; 2S,5R;2R,5R; and2R,5S) of chalcogran, a major component of the aggregation pheromone ofPityogenes chalcographus, and of all four isomers (2Z,4Z; 2Z,4E; 2E,4E; and 2E,4Z) of methyl 2,4-decadienoate (MD), the second major pheromone component, are briefly described. Attraction responses of walking beetles of both sexes were tested to mixtures of the synergistic pheromone components or analogs. These bioassays showed that theE,Z isomer of MD is the most active when tested with chalcogran. When tested with (E,Z)-MD, (2S,5R)-chalcogran was the most active stereoisomer, while 2R,5R and 2R,5S isomers had intermediate activities, and the 2S,5S isomer was inactive. There was no evidence that the relatively less active Stereoisomers of chalcogran inhibited or promoted attraction to (2S,5R)-chalcogran with (E,Z)-MD. Male beetles only produce the activeE,Z isomer of MD (inactive alone) and their hindguts contain the most active (2S,5R)- and least active (2S,5S)-chalcogran. A mixture of all MD isomers with racemic chalcogran was not significantly different in attractivity compared to (E,Z)-MD with racemic chalcogran, indicating no synergistic or inhibitory effects of the inactive isomers of MD.
    Type of Medium: Electronic Resource
    Location Call Number Expected Availability
    BibTip Others were also interested in ...
  • 3
    Electronic Resource
    Electronic Resource
    Springer
    Journal of chemical ecology 13 (1987), S. 2143-2157 
    ISSN: 1573-1561
    Keywords: Dendroctonus brevicomis ; Coleoptera ; Scolytidae ; pheromone ; synergism ; plumes ; exo-brevicomin ; frontalin ; myrcene
    Source: Springer Online Journal Archives 1860-2000
    Topics: Biology , Chemistry and Pharmacology
    Notes: Abstract The relationships between catch ofD. brevicomis LeC. at sources of the synergistic pheromone components,exo-brevicomin (E) and frontalin (F), and increasing distance of separation of sources were investigated in the forest. The two components were each released with the host monoterpene, myrcene (M), in trap pairs. The traps of each pair were spaced apart at various distances (0–16 m) in either horizontal or vertical lines that were perpendicular to the mean wind direction. Both sexes were most strongly attracted when the two components were released from the same source, and increasing distance of separation between components caused exponential decreases in trap catch for all trap configurations. Males were significantly more attracted to traps with E, M alone than to corresponding traps with F, M alone, while females exhibited a preference for F, M. The theoretical relationships and properties of two coalescing plumes of individual components and their intersecting “active space” are presented and discussed. It is proposed that “confusion” or “communication disruption” techniques for insect control may be more successful if components are released individually from many points rather than released similarly in blends.
    Type of Medium: Electronic Resource
    Location Call Number Expected Availability
    BibTip Others were also interested in ...
  • 4
    ISSN: 1573-1561
    Keywords: 2-Methyl-3-buten-2-ol ; cis-verbenol ; trans-verbenol ; myrtenol ; trans-myrtanol ; 2-phenylethanol ; ipsdienol ; subtractive assay ; Ips typographus ; Coleoptera ; Scolytidae ; Picea abies ; host volatiles
    Source: Springer Online Journal Archives 1860-2000
    Topics: Biology , Chemistry and Pharmacology
    Notes: Abstract Six compounds previously identified from hindguts of unmated maleIps typographus (L.) during host colonization: 2-methyl-3-buten-2-ol (MB),cis-verbenol (cV),trans-verbenol (tV), myrtenol (Mt),trans-myrtanol (tM), and 2-phenylethanol (PE), were tested for their attractivity in the field with a subtractive method. The amounts of MB and cV released from a pipe trap were similar to those given off from the commercial bait Ipslure as well as that from a Norway spruce tree,Picea abies (L.) Karst., under mass attack. The blend of the compounds became nonattractive when either MB or cV was subtracted, while subtraction of any of the other four compounds had no effect. Addition of ipsdienol (Id) to the blend did not significantly increase the attraction. In a second comparative test, the addition of three compounds as a group (tV + Mt + PE) to MB + cV again had no effect on the attraction, but the addition of Id increased the catch somewhat. Addition of host logs to a bait releasing MB + cV at a rate lower than in previous experiments did not influence the attraction to pipe traps. Sticky traps containing natural pheromone sources (50 males in a log), which released 1–5 mg/day of MB as determined by aerations with deuterated MB as internal standard, were less attractive than a synthetic source releasing similar amounts of MB.
    Type of Medium: Electronic Resource
    Location Call Number Expected Availability
    BibTip Others were also interested in ...
  • 5
    ISSN: 1573-1561
    Keywords: Host-plant selection ; Coleoptera ; Scolytidae ; Nitidulidae ; Rhizophagidae ; Calliphoridae ; Diptera ; semiochemical ; monoterpenes ; methanol ; ethanol ; propanol ; terpinolene ; α-pinene ; 3-carene ; verbenone
    Source: Springer Online Journal Archives 1860-2000
    Topics: Biology , Chemistry and Pharmacology
    Notes: Abstract Several Scandinavian forest insects,Hylurgops palliatus, Tomicus piniperda, andTrypodendron domesticum (Coleoptera: Scolytidae),Rhizophagus ferrugineus (Coleoptera: Rhizophagidae) andPollenia spp. (Diptera: Calliphoridae) were attracted to window traps baited with ethanol and placed on Scots pine trees (Pinus sylvestris) in May–June, 1986. Release of ethanol at increasing relative rates of 0, 0.01, 0.1 and 1.0 (800 mg/day) from the window traps on trees in 1987 causedH. palliatus, T. domesticum, andR. ferrugineus to be increasingly attracted, whileT. piniperda was equally attracted at both 0.1 and 1.0 rates. The attraction ofT. piniperda to ethanol was weak compared to attraction to a monoterpene mix, (±)-α-pinene, (+)-3-carene, terpinolene. The terpene mix plus ethanol was significantly more attractive toH. palliatus than ethanol alone, but terpenes significantly reduced the attraction ofT. domesticum to ethanol. Baiting of pipe traps with a series of short-chain alcohols (methanol to hexanol) each alone showed that ethanol was greatly preferred byH. palliatus, T. domesticum, andR. ferrugineus over alcohols of one more or one less carbon, while longer-chain alcohols were not attractive. However,Glischrochilus hortensis (Col.: Nitidulidae) was attracted only to propanol. A series of 10-fold increasing release rates of ethanol (0.0001-1.0, where 1.0=800 mg/day) with either a “low” or “high” release of the terpene mix had various effects on the sexes during their attraction to pipe traps and subsequent entering of holes. Release of (−)-verbenone at 0.25 mg/day had no significant effect onH. palliatus orR. ferrugineus attraction to ethanol, but the response ofT. domesticum to ethanol was reduced. Several theories on olfactory mechanisms of host selection byT. piniperda are integrated and placed in ecological perspective.
    Type of Medium: Electronic Resource
    Location Call Number Expected Availability
    BibTip Others were also interested in ...
  • 6
    ISSN: 1573-1561
    Keywords: 2-methyl-3-buten-2-ol ; cis-verbenol ; ipsdienol ; ipsenol ; sex ratio ; attraction ; inhibition ; Ips duplicatus ; Thanasimus ; switching ; Ips typographus ; Coleoptera ; Scolytidae ; Ceeridae
    Source: Springer Online Journal Archives 1860-2000
    Topics: Biology , Chemistry and Pharmacology
    Notes: Abstract The density of bark-beetle colonization of a tree could be regulated by a quantitative effect of the pheromone signal from beetles in the tree (cessation of release of attractive pheromone) or by a qualitative effect (production of pheromone components inhibiting attraction). The quantitative hypothesis was tested onIps typographus by varying the release rate of the two known attractive compounds, 2-methyl-3-buten-2-ol (MB) and (4S)-cis-verbenol (cV). The highest number of beetles were captured at traps with the highest release rates. The catch was nearly proportional to the release of MB and cV at a distance between traps of 12 m or more. At 6-, 3-, and 1.5-m distances between traps deployed in a triangular arrangement there was still a good discrimination between release rates, but relatively more beetles, especially males, were caught on the blank. The lower release rates caught an equal sex ratio while the highest release rate caught only about 30% males. The qualitative hypothesis was tested by releasing the suspected inhibitors ipsdienol (Id) and ipsenol (Ie), from traps in the same amounts as cV. Only small effects were noted forI. typographus. However, the competitorI. duplicatus was attracted to Id and inhibited by Ie, while the predatorThanasimus formicarius was attracted to both compounds. On the other hand, when the ratio of Id or Ie to cV was 10∶1 or 0.1∶1 rather than 1∶1, they affected the numbers ofI. typographus attracted. A small amount of Id combined with the attractants increased trap catch, while large amounts of Id or Ie decreased attraction, especially when combined. Attack density regulation is modeled as an effect of both quantitative and qualitative mechanisms acting in sequence.
    Type of Medium: Electronic Resource
    Location Call Number Expected Availability
    BibTip Others were also interested in ...
  • 7
    ISSN: 1573-1561
    Keywords: Host attraction ; pheromone ; Pinus sylveslris ; trans-verbenol ; 3-carene-10-ol ; myrtenol ; verbenone ; EAG ; kairomone ; Blastophagus ; Tomicus minor ; Tomicus piniperda ; Coleoptera ; Scolytidae ; pine shoot beetles
    Source: Springer Online Journal Archives 1860-2000
    Topics: Biology , Chemistry and Pharmacology
    Notes: Abstract The chemical ecology of host- and mate-finding in the pine shoot beetles,Tomicus minor andT. piniperda, was studied in southern Sweden. Beetles were collected in the field from defined attack phases on Scots pine. Using gas chromatography-mass spectroscopy, a number of oxygen-containing monoterpenes, e.g., 3-carene-10-ol, myrtenol,trans-verbenol, and verbenone, were identified from hindgut extracts of both sexes of both species. Compared toT. minor,T. piniperda contained additional compounds and in larger amounts. The amounts were highest in both species at the time when the beetles had bored into contact with the resin-producing xylem-phloem tissue. The synthesis of (1S,6R)-3-carene-10-ol by photooxidatipn of (+)-(1S,6R)-3-carene is described. In comparative electroantennogram (EAG) measurements on males and females of both species, the most active of the tested compounds wastrans-verbenol. Laboratory bioassays of walking beetles showed thatT. piniperda was attracted to uninfestèd pine logs.T. minor was more strongly attracted to pine logs infested with females than to uninfested pine logs, indicating a female-produced aggregation pheromone. Field tests confirmed thatT. piniperda was strongly attracted to pine logs. The attraction ofT. minor to logs was significant only when logs were combined with racemictrans-verbenol and (1S,6R)-3-carene-10-ol.T. minor was also attracted to a combination of these monoterpene alcohols alone. We suggest that host and mate location inT. piniperda is achieved by means of a kairomone composed of host monoterpenes, whileT. minor utilizes a primitive pheromone synergized by host odors. Evolution of host colonization strategies of the two beetles are discussed.
    Type of Medium: Electronic Resource
    Location Call Number Expected Availability
    BibTip Others were also interested in ...
  • 8
    ISSN: 1573-1561
    Keywords: Coleoptera ; Scolytidae ; Cleridae ; Dendroctonus brevicomis ; Enoclerus lecontei ; Pinus ponderosa ; bark beetle ; exo-brevicomin ; frontalin ; verbenone ; trans-verbenol ; ipsdienol ; aggregation ; pheromone ; competition
    Source: Springer Online Journal Archives 1860-2000
    Topics: Biology , Chemistry and Pharmacology
    Notes: Abstract Quantities of attractive (exo-brevicomin and frontalin) and inhibitory (trans-verbenol, verbenone, and ipsdienol) pheromones were monitored in both sexes ofDendroctonus brevicomis during their colonization of a ponderosa pine. Verbenone was found in males in the greatest amounts at the time of landing, and it declined more rapidly than the other pheromones in either sex. The amounts of frontalin andexo-brevicomin in males and females, respectively, increased after initial boring within the host but began to decline after mating. The quantity oftrans-verbenol in both sexes (females had significantly more) declined more gradually thanexo-brevicomin, frontalin, and verbenone. Ipsdienol was found only in males during the initial stages of attack when encountering the resin. It is suggested that along with a general decline in all pheromonal components, a sufficient change in the ratio of the attractive pheromones to an inhibitory pheromone,trans-verbenol, may play a role in termination of aggregation.trans-Verbenol may also function along with verbenone and ipsdienol in limiting the density of attack and thus intraspecific competition. These inhibitory pheromones also appear to cause several competing species of bark beetle to avoid landing in areas infested withD. brevicomis, even when their own pheromone is present.
    Type of Medium: Electronic Resource
    Location Call Number Expected Availability
    BibTip Others were also interested in ...
  • 9
    ISSN: 1573-1561
    Keywords: Pheromone ; bark beetle ; Coleoptera ; Scolytidae ; Pityogenes chalcographus ; methyl (E,Z)-2,4-decadienoate ; chalcogran ; Picea abies ; synergist ; subtractive-combination bioassay ; two-dimensional fractionation
    Source: Springer Online Journal Archives 1860-2000
    Topics: Biology , Chemistry and Pharmacology
    Notes: Abstract Capillary gas chromatography with columns of different polarity and two-dimensional fractionation of effluents were used with novel subtrac-tive-combination bioassays to rigorously isolate host- and insect-produced pheromone synergists of the bark beetlePityogenes chalcographus (Coleop-tera: Scolytidae). Methyl (E,Z)-2,4-decadienoate (E,Z-MD) and the previously identified chalcogran were found to be synergistically attractive to both sexes.E,Z-MD was produced sex-specifically in males, and only when they had fed on host-plant tissue. A Norway spruce monoterpene fraction (including α-pinene, β-pinene, and camphene) increased the attractive response to the pheromone components. Dose-response curves forE,Z-MD and chalcogran in the laboratory bioassay indicated the two components are highly synergistic. The isolation methods are important for further progress in identifying certain semiochemical synergists found in trace amounts in complex chemical mixtures, such as when insects must feed in host plants in order to produce pheromone.
    Type of Medium: Electronic Resource
    Location Call Number Expected Availability
    BibTip Others were also interested in ...
  • 10
    ISSN: 1573-1561
    Keywords: Host selection ; dispenser ; release rates ; Coleoptera ; Scolytidae ; Pityogenes bidentatus ; Pinus sylvestris ; Scotch pine ; conifers
    Source: Springer Online Journal Archives 1860-2000
    Topics: Biology , Chemistry and Pharmacology
    Notes: Abstract A piezoelectric sprayer for dispensing semiochemicals was developed and used for a field test of bark beetle semiochemicals. The sprayer consists of a geared pump that pushes a syringe slowly to dispense semiochemicals in solvents through a microtube to a glass micropipet fixed to a piezoelectric high-frequency vibrator. The frequency is adjusted via a function generator to about 120 kHz until the harmonic properties of the glass micropipet, drawn by an electrophysiological pipet puller, cause vibrations that atomize the solvent from the micropipet tip. The sprayer, syringe, pump, function generator, and power supply were hung on one arm of a rotating trap pair (traps 6 m apart) that was slowly rotated at 2 revolutions per hour (rph) to even out the position effects on trap catches. The aggregation pheromone components of Pityogenes bidentatus, grandisol and cis-verbenol, were released by standard tube dispensers in one trap and compared to the release of similar amounts by the sprayer in the other trap. No significant differences in catch were observed. No effect of the solvent hexane on aggregation could be observed. The trap pair also caught approximately equal numbers of bark beetles when the baits were identical. The release of (+)and (−)-α-pinene, (+)-3-carene, and terpinolene, monoterpenes of host Scotch pine, Pinus sylvestris, at increasing rates from 0.01 to 10 log-equivalents in decadic steps (each at 0.1–100 μg/min) resulted in decreasing responses to aggregation pheromone (only 9% at highest rate). Inhibition by the individual monoterpenes tested at the 100 μg/min rate was significant for (+)and (−)-α-pinene and terpinolene (12, 13, and 15% of control, respectively). The inhibition by the host Scotch pine monoterpenes may allow P. bidentatus to avoid resistant trees that release large amounts of toxic monoterpenes in their resin and instead colonize dying and diseased limbs or slash, the usual host substrate. The piezoelectric sprayer should prove generally useful to dispense precise amounts of semiochemicals in field and laboratory experiments.
    Type of Medium: Electronic Resource
    Location Call Number Expected Availability
    BibTip Others were also interested in ...
Close ⊗
This website uses cookies and the analysis tool Matomo. More information can be found here...