Endoparasitoid wasps can develop inside permissive host due to their ability to overcome or to evade the host’s cellular and humoral immune response. Oviposition of Campoletis chlorideae (Hymenoptera: Ichneumonidae) ...Endoparasitoid wasps can develop inside permissive host due to their ability to overcome or to evade the host’s cellular and humoral immune response. Oviposition of Campoletis chlorideae (Hymenoptera: Ichneumonidae) in larvae of Helicoverpa armigera (Lepidoptera) was accompanied by inhibition of phenoloxidase (PO) activity and melanization reaction in host hemolymph in vitro. PO activity in host plasma was decreased about 83% 48 h post para-sitization. A similar result was found when the host insect was injected with 0.5 wasp equivalent calyx fluid. This indicated that the calyx fluid was concerned with suppression of PO activity after parasitization. Furthermore, the prophen-oloxidase (proPO) in host haemocytes could be activated by bovine trypsin in unparasitized insects, while it could not be activated in parasitized or calyx fluid-injected host. The results suggested that inhibition of PO activity by parasitization was related to the calyx fluid of Campoletis chlorideae, and the components of calyx展开更多
基金This work was supported by a special fund for the Major State Basic Research Project of China (Grant No. 2000016208) and the National Natural Science Foundation of China (Grant No. 30070517).
文摘Endoparasitoid wasps can develop inside permissive host due to their ability to overcome or to evade the host’s cellular and humoral immune response. Oviposition of Campoletis chlorideae (Hymenoptera: Ichneumonidae) in larvae of Helicoverpa armigera (Lepidoptera) was accompanied by inhibition of phenoloxidase (PO) activity and melanization reaction in host hemolymph in vitro. PO activity in host plasma was decreased about 83% 48 h post para-sitization. A similar result was found when the host insect was injected with 0.5 wasp equivalent calyx fluid. This indicated that the calyx fluid was concerned with suppression of PO activity after parasitization. Furthermore, the prophen-oloxidase (proPO) in host haemocytes could be activated by bovine trypsin in unparasitized insects, while it could not be activated in parasitized or calyx fluid-injected host. The results suggested that inhibition of PO activity by parasitization was related to the calyx fluid of Campoletis chlorideae, and the components of calyx
