荔蝽卵平腹小蜂辨别寄主能力的研究

在室内以柞蚕卵为寄主,研究荔蝽卵平腹小蜂辨别寄主的能力.结果表明,荔蝽卵平腹小蜂可以分别在寄主卵外和寄主卵内辨别被同种雌性寄生过的寄主卵,辨别能力随着寄主卵被寄生后的时间长短和寄主卵的密度大小而变化.在寄主卵外辨别已寄生寄主的能力随着寄主卵被寄生后时间的延长和寄主卵密度的减小而减弱;而在寄主卵内辨别寄主的能力却随着寄主卵被寄生后时间的延长而增强,寄主卵密度对平腹小蜂在寄主卵内辨别寄主的能力无明显的影响.荔蝽卵平腹小蜂还可以在寄主卵外辨别是自身或是同种其他雌蜂寄生过的寄主卵,但在寄主卵内无此辨别能力.

Intraspecific Host Discrimination of Anastatus japonicus Ashmead(Hymenoptera:Eupelimidae)

Intraspecific host discrimination of Anastatus japonicus Ashmead,an important egg parasite of the litchi stink bug Tessaratoma papilosa Drury,was investigated in the laboratory.A.japonicus was able to distinguish between unparasitized and parasitized hosts externally as well as internally,but there was differ- ence in frequence of host discrimination with host parasitized over varying periods.The host discrimination of A.japonicus based on the internal examination did not occour until 7 days after hosts were parasitized by the lst female.There was a positive effect of host density on host discrimination of A.japonicus based on the external examination,but no effect on the discrimination based on the internal examination.A.japonicus also could distinguish directly between self and conspccifically parasitized hosts.