Phenolics as ecologically relevant cues for slime flux breeding Drosophila virilis

Drosophila species belonging to the virilis group offer a unique opportunity for studying olfactory adaptations necessary for survival within forest ecosystems as many of these species breed within decaying plant vascular tissues. However, the knowledge regarding olfactory preferences within their ecological niche is extremely limited. Here, we focus on Drosophila virilis and identify over 120 distinct odors from a natural slime flux source. We identify lignin as an attractant and a positive oviposition cue for D. virilis. Furthermore, lignin-derived guaiacol is highlighted as a robust attractant for D. virilis. We demonstrate that guaiacol is detected by the DvirOr49b receptor, which exhibits a narrow sensitivity to methylphenols, including o-cresol. D. virilis and D. ezoana, both belonging to the virilis group, exhibit strong attraction to o-cresol. In summary, our research offers a comprehensive analysis of the diverse array of odorants encountered by D. virilis within its natural habitat and their behavioral significance.