The invasive fly Drosophila suzukii is a pest that can infest a diverse range of intact, ripening fruits, using its serrated ovipositor. This constitutes a different niche compared to the rotting fruits its ancestors use, especially because these intact fruits have limited quantities of microbes and soluble nutrients for the developing larvae. To investigate the potential role of microbial associations in the niche expansion of this invasive fly, we characterized the bacterial and fungal communities of D. suzukii and various wild fruits from which they developed. To assess cross-generational microbial associations, we also lab-reared fly populations and characterized their microbial communities. Diversity metrics of microbial communities differed significantly between flies and fruits. Different fruit types varied substantially in microbial composition, while flies showed relatively uniform bacterial communities, irrespective of the fruit source they developed on. After approximately ten generations of lab-rearing, bacterial communities still showed considerable overlap with those of wild flies. Fungal communities of flies and fruits showed larger resemblance, with a substantial overlap between wild flies and the fruits on which they had developed. Our study thus reports that the fungal community structure in these pests largely reflects those on the breeding substrates, while these flies might have formed more persistent associations with some bacteria and transmit these across generations.

入侵果蝇铃木果蝇是一种害虫，可以利用其锯齿状产卵器侵染各种完整、成熟的水果。与其祖先使用的腐烂水果相比，这构成了一个不同的生态位，特别是因为这些完整的水果含有有限数量的微生物和发育中的幼虫的可溶性营养物质。为了研究微生物关联在这种侵入性苍蝇的生态位扩张中的潜在作用，我们对D. suzukii的细菌和真菌群落进行了表征以及它们从中发育而来的各种野果。为了评估跨代微生物关联，我们还在实验室饲养了苍蝇种群并描述了它们的微生物群落。微生物群落的多样性指标在苍蝇和水果之间存在显着差异。不同水果类型的微生物组成差异很大，而果蝇则表现出相对均匀的细菌群落，而与它们发育的水果来源无关。经过大约十代的实验室饲养，细菌群落与野生苍蝇的群落仍然表现出相当大的重叠。苍蝇和果实的真菌群落表现出更大的相似性，野生苍蝇与其发育的果实之间存在大量重叠。