ISSN:
1573-1561
Keywords:
Chemical defense
;
feeding behavior
;
glandular trichomes
;
Helianthus
;
herbivory
;
Homoeosoma electellum
;
Lepidoptera
;
Pyralidae
;
host-plant resistance
;
plant-insect interactions
;
sesquiterpene lactones
;
terpenoids
Source:
Springer Online Journal Archives 1860-2000
Topics:
Biology
,
Chemistry and Pharmacology
Notes:
Abstract The responses of a sunflower specialist,Homoeosoma electellum, the sunflower moth, to the terpenoids produced by its host plant,Helianthus, were measured. Larvae were reared on synthetic diet containing one of three concentrations of the dominant sesquiterpene lactone found in glandular trichomes ofH. maximilliani. Treatments were initiated at each of three larval ages. Pupal weight was significantly reduced, but the effect diminished as the larvae aged. Survival and development time were unaffected by various treatments. In behavioral tests, larvae showed no preference for untreated synthetic diet compared to diet containing the secondary compound at a concentration of 1% by dry weight. When the concentration was raised to 5%, all but last-instar larvae showed a significant preference for the untreated diet. A second behavioral test measured the damage done to whole florets and an array of floral parts offered to larvae of different ages. The damage pattern of floral tissues changed as the larvae grew older, demonstrating that the willingness of larvae to eat tissues contaminated with trichome contents increased with age. The value of the glandular trichome contents as a defense againstH. electellum is discussed.
Type of Medium:
Electronic Resource
URL:
http://dx.doi.org/10.1007/BF01012368
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