在不同寄生物物种之间的内在竞争相互作用(多寄生物)期间,寄生物在寄生物中的共存或位移可能取决于它们的生活史特征和行为。争夺宿主的激烈竞争可能会导致通过人身攻击和/或生理抑制来淘汰劣等竞争对手。然而,多寄生期间的生理抑制机制尚不清楚。先前的工作表明,孤立的内寄生虫Meteoruspulchricornis的第一龄幼虫具有发达的下颌骨,可用于杀死竞争对手。两种群居性内寄生虫,CotesiaKariyai和C.Rufricus,共享宿主资源,尤其是在产卵时间间隔较短的情况下。这里,我们调查了黄蜂调节因子对三种内寄生虫的生理影响,M.pulchricornis,C.kariyai,还有C.ruficrus,在他们的共同宿主Mythimnaseparata中。我们发现MpVLP单独(或与毒液一起)有害地影响了这两个群居物种的发育。同样,CkPDV加毒液对猪笼草卵和未成熟幼虫有毒性作用,尽管它们对C.ruficrus的未成熟阶段无害。Cotesiakariyai和C.ruficrus能够主要通过调节因子的表达共存,并且两者都可以成功地从多寄生宿主中出现。在L5寄主幼虫产卵后注射CkPDV加毒液促进了C.ruficrus的发育,并将成功的寄生率从9%提高到62%。这表明这两个群居性的类寄生虫黄蜂表现出很强的系统发育亲和力,支持它们在多寄生宿主中的共存和成功。
Coexistence or displacement of parasitoids in hosts during intrinsic competitive interactions between different parasitoid species (multiparasitism) may depend on their life history traits and behavior. Intense competition for possession of hosts may lead to the elimination of the inferior competitor through physical attack and/or physiological suppression. However, the mechanisms of physiological suppression during multiparasitism remain unclear. Previous work has shown that first instar larvae of the solitary endoparasitoid Meteorus pulchricornis possess well-developed mandibles that are used to kill competitors. Two gregarious endoparasitoids, Cotesia kariyai and C. rufricus, share host resources especially when the time gap of oviposition is short. Here, we investigated the physiological influence of wasp-regulatory factors of the three endoparasitoids, M. pulchricornis, C. kariyai, and C. ruficrus, in their common host Mythimna separata. We found that MpVLP alone (or with venom) deleteriously affected the development of the two gregarious species. Similarly, CkPDV plus venom had toxic effect on M. pulchricornis eggs and immature larvae, although they were not harmful to immature stages of C. ruficrus. Cotesia kariyai and C. ruficrus were able to coexist mainly through the expression of regulatory factors and both could successfully emerge from a multiparasitized host. The injection of CkPDV plus venom after oviposition in L5 host larvae facilitated C. ruficrus development and increased the rate of successful parasitism from 9% to 62%. This suggests that the two gregarious parasitoid wasps exhibit strong phylogenetic affinity, favoring their coexistence and success in multiparasitized hosts.