中红侧沟茧蜂在粘虫体内的发育及畸形细胞发生

Embryogenesis and larval development of Microplitis mediator parasitizing Mythimna separata and occurrence of teratocytes

中红侧沟茧蜂Microplitismediator的初产卵因受雌蜂产卵器的机械挤压 ,在形态上有别于未产出的卵 ,这种机械挤压激活了蜂卵的胚胎发育。产卵后 6h ,胚带和浆膜层开始分化 ,2 0h胚胎成形 ,包裹在单层细胞的浆膜层内。 32～ 34h ,幼蜂孵化 ,顶部的浆膜层立即分散形成畸形细胞 ,尾部的浆膜层则逐渐释放细胞。 1龄幼蜂具一对角质的颚 ,用来消灭同种竞争者。寄生后10 8～ 113h ,1龄幼蜂蜕皮进入 2龄。 2龄幼蜂为无头型 ,尾囊发达。成熟的畸形细胞 (受寄生日龄 6天 )表面密布微绒毛 ,细胞内部高尔基体丰富 ,内质网发达 ,细胞核多分支。在高尔基体的两侧和细胞膜附近分布了大量的分泌小池。

The shape of newly laid eggs of the wasps Microplitis mediator is different from that of the eggs in the calyx region, due to mechanical press while they pass through the ovipositors, which initiates the development of the embryos. Six hours after oviposition, the embryo attains the germ band stage, and a serosal membrane is observed. Hatching occurs at 32～34 h. Immediately after hatching, the cells from the upper serosal membrane of the embryo disperse to form teratocytes in the haemocoele of the host, while those from the lower part are released gradually. The 1st instar larva has a pair of sclerotized mandibles, which are used as a weapon to fight with its con species competitors. A caudal sac is well developed after the larva enters its 2nd instar at 108～113 h. The surface of a mature teratocyte (6 days after parasitization) is covered with numerous microvilli. A vesiculated endoplasmic reticulum system disperses throughout the cytoplasm in which many Golgi complexes exist too. The nucleus is extensively ramified.