Interkingdom competition occurs between hymenopteran parasitoids and insect viruses sharing the same insect hosts. It has been assumed that parasitoid larvae die with the death of the infected host or as result of competition for host resources. Here we describe a gene family, parasitoid killing factor (pkf), that encodes proteins toxic to parasitoids of the Microgastrinae group and determines parasitism success. Pkfs are found in several entomopathogenic DNA virus families and in some lepidopteran genomes. We provide evidence of equivalent and specific toxicity against endoparasites for PKFs found in entomopoxvirus, ascovirus, baculovirus, and Lepidoptera through a mechanism that elicits apoptosis in the cells of susceptible parasitoids. This highlights the evolutionary arms race between parasitoids, viruses, and their insect hosts.

膜翅目寄生蜂和共享相同昆虫宿主的昆虫病毒之间发生界际竞争。已经假设寄生蜂幼虫随着受感染宿主的死亡或宿主资源的竞争而死亡。在这里，我们描述了一个基因家族，即寄生蜂杀伤因子( pkf )，它编码对小胃螟亚科的寄生蜂有毒并决定寄生成功率的蛋白质。PKFS在几个昆虫病原 DNA 病毒家族和一些鳞翅目基因组中发现。我们提供了对昆虫痘病毒、囊状病毒、杆状病毒和鳞翅目中发现的 PKF 的体内寄生虫具有等效和特异性毒性的证据，该机制通过一种引起易感寄生虫细胞凋亡的机制。这凸显了寄生蜂、病毒及其昆虫宿主之间的进化军备竞赛。