Title: A Compound Produced by Fruigivorous Tephritidae (Diptera) Larvae Promotes Oviposition Behavior by the Biological Control Agent Diachasmimorpha Longicaudata (Ashmead) (Hymenoptera: Braconidae) Authors
Submitted to: Meeting Abstract
Publication Type: Abstract Only
Publication Acceptance Date: September 26, 2010
Publication Date: N/A
Technical Abstract: Tephritid parasitoids use fruit-derived chemical cues and the vibrations that result from larval movements to locate hosts sequestered inside fruit. However, compounds produced by the larvae themselves have not been previously described nor their significance to parasitoid foraging determined. We collected the volatiles from four species of tropical/subtropical Tephritidae (Anasterpha suspensa (Loew), Bactrocera dorsalis (Hendel), Bactrocera cucurbitae (Coquillett) and Ceratitis capitata (Weidimann), representing two subfamilies (Dacinae and Tryptinae). Para-ethylacetophenone, an analog of a known tephritid parasitoid attractant, was a major constituent of all four, and was not associated with larvae of another acalypterate fly, Drosophila melanogaster Meigen, or with the calypterate Musca domestica L.. It was also present in volatiles from whole, A. suspensa infested fruits of Eugenia uniflora (L.). While collected in this study as a volatile, it was presumably also present in the fluid surrounding larvae inside fruit. Para-ethylacetophenone was not necessarily produced as a direct consequence of fruit consumption since it was also detected from larvae that developed in two artificial diets and in “spent” diets subsequent to larval development. Sensillae on both the antennae and ovipositor of the opiine braconid fruit fly parasitoid, Diachasmimorpha longicaudata (Ashmead) responded to the para-ethylacetophenone in larval volatiles and as a synthetic. While a potential cue to foraging parasitoids, para-ethylacetophenone showed no long range (>1m) attractiveness to the parasitoid, but did stimulate ovipositor-insertion and oviposition into both a natural (fruit) and an artificial (parafilm) substrate. Para-ethylacetophenone may prove useful in stimulating oviposition and so aid in colonizing and mass-rearing opine fruit fly parasitoids.