The use of entomopathogenic fungi for pest control is gaining increasing attention. These fungi act as contact biological insecticides but also via endophytic colonization of targeted crops. In addition, the joint use of entomopathogenic fungi and natural enemies hold potential in many pest control programs. Here, we evaluated in vitro and in planta multitrophic interactions among the endophytic fungus Metarhizium brunneum colonizing melon (Cucumis melo) plant, the parasitoid Hyposoter didymator and the pest Spodoptera littoralis. In all experiments, total mortality of S. littoralis larvae was significantly affected by the presence of the parasitoid; the treatments including the parasitoid achieved the highest mortality rates both in vitro and in planta. Simultaneous exposure to the fungus and the parasitoid did not significantly increase the total mortality of S. littoralis larvae than the parasitoid alone. The time between exposure to fungus and parasitoid attack did not affect S. littoralis mortality, nor parasitism (parasitoid) or infection rates (fungus). However, the parasitoid showed a significant preference for larvae fed on control plants (24.4% parasitism) compared with larvae fed on fungus-colonized plants (4.4%). A histological study of S. littoralis larvae simultaneously attacked by H. didymator and M. brunneum showed, for the first time, the coexistence of both agents within the same host; parasitoid larvae developed inside the host despite fungal colonization. This provides key information about intra-host interactions between two important biological control agents when used together for S. littoralis control.

昆虫病原真菌的使用越来越受到人们的关注。这些真菌不仅充当接触性生物杀虫剂，而且还通过目标作物的内生菌落定植。此外，在许多害虫防治计划中，昆虫病原真菌和天敌的联合使用具有潜力。在这里，我们在体外和评估在植物的内生真菌之间的相互作用multitrophic绿僵brunneum定植甜瓜（甜瓜）厂，寄生Hyposoter didymator和害虫斜纹夜蛾。在所有实验中，滨海链球菌的总死亡率幼虫受寄生虫的影响显着；无论是在体外还是在植物中，包括寄生物在内的治疗死亡率最高。同时暴露于真菌和类寄生虫并没有比单独的类寄生虫显着增加滨海链球菌幼虫的总死亡率。接触真菌与类寄生虫侵袭之间的时间不会影响滨海链球菌的死亡率，也不会影响寄生虫（类寄生虫）或感染率（真菌）。然而，与以真菌定植的植物（4.4％）饲喂的幼虫相比，拟寄生虫对以对照植物为食的幼虫表现出明显的偏爱（24.4％寄生）。同时受侵袭的滨海链球菌幼虫的组织学研究。H. Didymator和M. brunneum首次展示了两种媒介在同一宿主中共存。尽管有真菌定植，但寄生虫的幼虫仍在宿主体内发育。当一起用于滨海链球菌控制时，这提供了有关两个重要生物控制剂之间的宿主内部相互作用的关键信息。