Comparison of Preference for Chemicals Associated with Fruit Fermentation between Drosophila melanogaster and Drosophila suzukii and between Virgin and Mated D. melanogaster

Abstract

Two taxonomically similar Drosophila species, Drosophila melanogaster and Drosophila suzukii, are known to have distinct habitats: D. melanogaster is mostly found near overripe and fermented fruits, whereas D. suzukii is attracted to fresh fruits. Since chemical concentrations are typically higher in overripe and fermented fruits than in fresh fruits, D. melanogaster is hypothesized to be attracted to higher concentrations of volatiles than D. suzukii. Therefore, the chemical preferences of the two flies were compared via Y-tube olfactometer assays and electroantennogram (EAG) experiments using various concentrations of 2-phenylethanol, ethanol, and acetic acid. D. melanogaster exhibited a higher preference for high concentrations of all the chemicals than that of D. suzukii. In particular, since acetic acid is mostly produced at the late stage of fruit fermentation, the EAG signal distance to acetic acid between the two flies was higher than those to 2-phenylethanol and ethanol. This supports the hypothesis that D. melanogaster prefers fermented fruits compared to D. suzukii. When comparing virgin and mated female D. melanogaster, mated females showed a higher preference for high concentrations of chemicals than that of virgin females. In conclusion, high concentrations of volatiles are important attraction factors for mated females seeking appropriate sites for oviposition.

Electrophysiological and Behavioral Responses of Virgin Female Bactrocera tryoni to Microbial Volatiles from Enterobacteriaceae

“…For instance, esters prevailed in apples, while hydrocarbons and terpenes were mostly present in kiwis and oranges, respectively. While we did not find strong microbially induced specific fruit volatile profiles, the overall abundance of volatiles (i.e., esters, terpenes, alcohol, and aromatics, which were previously described in other fruits commonly attractive to Tephritidae fruit flies [45][46][47]) was enhanced with incubation time with Enterobactereriacea. For instance, a positive correlation was found between the proportion of compounds emitted by kiwifruit and the incubation time (e.g., more D-limonene was produced at 24 h post-inoculation).…”