While the majority of Drosophila species lays eggs onto fermented fruits, females of Drosophila suzukii pierce the skin and lay eggs into ripening fruits using their serrated ovipositors. The changes of oviposition site preference must have accompanied this niche exploitation. In this study, we established an oviposition assay to investigate the effects of commensal microbes deposited by conspecific and heterospecific individuals and showed that the presence of microbes on the oviposition substrate enhances egg laying of Drosophila melanogaster and Drosophila biarmipes, but discourages that of D. suzukii. This result suggests that a drastic change has taken place in the lineage leading to D. suzukii in how females respond to chemical cues produced by microbes. We also found that hardness of the substrate, resembling that of either ripening or damaged and fermenting fruits, affects the response to microbial growth, indicating that mechanosensory stimuli interact with chemosensory-guided decisions to select or avoid oviposition sites.

果蝇大多数种类都将卵产在发酵的果实上，而铃木果蝇的雌性则使用锯齿状的排卵器刺穿皮肤并将卵产于成熟的果实中。产卵地点偏好的变化必然伴随着这种利基的开发。在这项研究中，我们建立了一种产卵试验，以研究同种和异种个体沉积的共生微生物的影响，并显示产卵基质上存在的微生物增强了果蝇和果蝇的产卵能力，但不鼓励铃兰果蝇的产卵。。该结果表明血统发生了巨大变化，导致铃木D.（D. suzukii）女性如何应对微生物产生的化学信号。我们还发现，基质的硬度（类似于成熟或受损和发酵的果实）会影响对微生物生长的响应，这表明机械感官刺激与化学感官指导的决定相互作用，以选择或避免产卵。