Electroantennogram and oviposition responses ofEpiphyas postvittana(Lepidoptera: Tortricidae) to plant volatiles

Abstract

Electroantennogram (EAG) responses of male and female Epiphyas postvittana (lightbrown apple moth) were recorded to plant volatiles delivered from either filter paper or a gas chromatograph. Males showed significantly higher EAG responses than females with both methods (P < 0.001). Responsiveness to compounds was significantly correlated between sexes and between methods (P < 0.01). Pairs of moths were caged with access to filter paper treated with plant volatiles, and untreated filter paper, for oviposition. The number of females ovipositing, the number of eggs laid, and the proportion of total eggs laid on the treated paper were recorded to determine the attractancy or repellency of the compounds. Eugenol, geraniol, and citral deterred oviposition, whereas hexanal, linalool, nonanol, octanol, and nonanal were attractants. The proportion of females laying eggs was reduced in the presence of citral, nonanol, octanol, and n-decyl aldehyde. The number of fertile eggs laid per female was reduced by 10 of the 14 compounds tested. EAG was a poor predictor of oviposition attractancy or repellency. Stimulation with fresh plant foliage produced significantly higher EAGs in eight host plants, compared to eight nonhosts (P< 0.001).

Synthetic Grape Volatiles Attract Mated Lobesia botrana Females in Laboratory and Field Bioassays

“…In this way, the behavior of L. botrana is similar to that of other tortricids (Wearing and Hutchings 1973;Suckling et al 1996;Grant et al 2007). On the other hand, the plasticity in the responses of L. botrana to ubiquitous plant compounds at different ratios can also explain the keeping of several plant species and grape varieties as hosts that provide different fitness (Thiéry and Moreau 2005;Tasin et al 2007).…”

Plant Volatiles Influence Electrophysiological and Behavioral Responses of Lygus hesperus

“…In general, although males showed stronger responses than females, both L. hesperus genders showed strong EAG responses to the highly volatile GLVs, whereas behavioral responses to plant volatiles varied widely between genders and among different chemical classes, and, thus, was uncorrelated to the volatiles' emission rates. Inconsistencies between electrophysiological and behavioral results are not uncommon (Mayer et al 1984;Suckling et al 1996;Wee et al 2008), and illustrate the importance of using multiple research approaches. Here, we provide three possible explanations for these discrepancies.…”

Volatiles from Apple Trees Infested with Light Brown Apple Moth Larvae Attract the Parasitoid Dolichogenidia tasmanica

“…19,20 However, there has been less enquiry into volatiles from apple foliage, although terpene-mediated parasitoid host location behavior to leafminer attack was documented on transgenic and classically bred apple genotypes. 16 Apple fruit are used by E. postvittana only incidentally; 21,22 therefore, it is more likely that attraction to apple trees by adult female LBAM (and potentially parasitoids) will be mediated by foliage volatiles. 22 Apart from the economic interest in the adventive pest and its biological control, of interest here is the novel combination of an Eurasian perennial tree (M. domestica) being attacked by an Australian herbivore (Tortricidae) and a parasitoid responding to the plant signaling from the Eurasian plant and probably many other landscape plants in New Zealand.…”

“…16 Apple fruit are used by E. postvittana only incidentally; 21,22 therefore, it is more likely that attraction to apple trees by adult female LBAM (and potentially parasitoids) will be mediated by foliage volatiles. 22 Apart from the economic interest in the adventive pest and its biological control, of interest here is the novel combination of an Eurasian perennial tree (M. domestica) being attacked by an Australian herbivore (Tortricidae) and a parasitoid responding to the plant signaling from the Eurasian plant and probably many other landscape plants in New Zealand. 23 We chose to examine the apple−leafroller system with the solitary wasp Dolichogenidea tasmanica (Hymenoptera: Braconidae), a larval endoparasitoid of first and second instar leafroller larvae, because this parasitoid can locate and attack at least three species of economically important leafrollers on apples from Australia and New Zealand.…”