Data from: Attraction, oviposition and larval survival of the fungus gnat, Lycoriella ingenua, on fungal species isolated from adults, larvae, and mushroom compost

We previously showed that the females of the mushroom sciarid, Lycoriella ingenua (Dufour, 1839) (Diptera: Sciaridae), one of the most severe pests of the cultivated white button mushroom, Agaricus bisporus (J.E. Lange) Emil J. Imbach (Agaricales: Agaricaceae), are attracted to the mushroom compost that mushrooms are grown on and not to the mushrooms themselves. We also showed that females are attracted to the parasitic green mold, Trichoderma aggressivum. In an attempt to identify what is in the mushroom compost that attracts female L. ingenua, we isolated several species of fungi from adult males and females, third instar larvae, and mushroom compost itself. We then analyzed the attraction of females to these substrates using a static-flow two choice olfactometer, as well as their oviposition tendencies in another type of assay under choice and no-choice conditions. We also assessed the survival of larvae to adulthood when first instar larvae were placed on each of the isolated fungal species. We found that female flies were attracted most to the mycoparasitic green mold, T. aggressivum, to Penicilium citrinum isolated from adult female bodies, and to Scatylidium thermophilium isolated from the mushroom compost. Gravid female flies laid the most eggs on T. aggressivum, Aspergillus flavus isolated from third instar larval frass, Aspergillus fumigatus isolated from adult male bodies, and on P. citrinum. This egg-laying trend remained consistent under no-choice conditions as females aged. First instar larvae developed to adulthood only on S. thermophilium and Chaetomium sp. isolated from mushroom compost, and on P. citrinum. Our results indicate that the volatiles from a suite of different fungal species act in tandem in the natural setting of mushroom compost, with some first attracting gravid female flies and then others causing them to oviposit. The ecological context of these findings is important for creating an optimal strategy for using possible semiochemicals isolated from these fungal species to better monitor and control this pestiferous mushroom fly species.

本团队前期研究证实，作为栽培白纽扣蘑菇（双孢蘑菇*Agaricus bisporus* (J.E. Lange) Emil J. Imbach，伞菌目（Agaricales）蘑菇科（Agaricaceae））的主要害虫之一，双翅目（Diptera）眼蕈蚊科（Sciaridae）的蘑菇眼蕈蚊*Lycoriella ingenua*（Dufour, 1839）的雌成虫会被栽培蘑菇所用的堆肥吸引，而非蘑菇本身。此外本团队还发现，该雌成虫同样会被寄生性绿霉——深绿木霉（*Trichoderma aggressivum*）所吸引。为明确蘑菇堆肥中吸引*L. ingenua*雌成虫的活性成分，本研究从成虫（雌雄个体）、3龄幼虫以及蘑菇堆肥中分离得到多株真菌。随后，本研究采用静态流型双选择嗅觉仪，分析雌成虫对这些真菌底物的趋性；同时通过一套包含选择与非选择两种条件的实验，评估雌成虫的产卵偏好。此外，本研究还将1龄幼虫接种至各分离真菌底物上，统计其发育至成虫的存活率。实验结果显示，雌成虫对以下底物的趋性最强：重寄生绿霉深绿木霉（*T. aggressivum*）、从雌成虫体内分离的桔青霉（*Penicilium citrinum*），以及从蘑菇堆肥中分离的嗜热侧孢霉（*Scatylidium thermophilium*）。怀卵雌成虫的产卵量最高的底物依次为：深绿木霉（*T. aggressivum*）、从3龄幼虫虫粪中分离的黄曲霉（*Aspergillus flavus*）、从雄成虫体内分离的烟曲霉（*Aspergillus fumigatus*），以及桔青霉（*P. citrinum*）。随着雌成虫日龄增长，该产卵偏好趋势在非选择实验中始终保持稳定。仅在从蘑菇堆肥中分离的嗜热侧孢霉（*S. thermophilium*）、毛壳菌属（*Chaetomium* sp.）物种，以及桔青霉（*P. citrinum*）底物上，1龄幼虫才能顺利发育至成虫阶段。本研究结果表明，在蘑菇堆肥的自然生境中，多种真菌释放的挥发性物质协同发挥作用：部分真菌的挥发性物质先吸引怀卵雌成虫，其余则诱导其产卵。本研究的生态学背景可为利用从上述真菌中分离得到的潜在信息化合物，构建针对该蘑菇害虫的高效监测与防控策略提供理论依据。