两种烟粉虱寄生蜂的雌性生殖系统结构与卵巢发育特点

 通过对烟粉虱Bemisia tabaci Gennadius 的两种优势寄生蜂浅黄恩蚜小蜂Encarsia sophia Girault & Dodd 和海氏桨角蚜小蜂Eretmocerus hayati Zolnerowich & Rose 的生殖系统结构与卵巢发育特点的研究,明确了影响两种寄生蜂不同寄主处理行为的生理机制。两种寄生蜂雌性生殖系统各包括1 对卵巢、1 对侧输卵管、中输卵管、受精囊、产卵管和产卵鞘。浅黄恩蚜小蜂的产卵器细长笔直较锋利,海氏桨角蚜小蜂产卵器扁平且尖端向上弯曲,这与两种寄生蜂不同的产卵机制相吻合。浅黄恩蚜小蜂和海氏桨角蚜小蜂雌蜂初羽化时体内成熟卵子数量存在明显差异,但随着时间的推移和营养的补充,两种寄生蜂卵巢内成熟卵子的数量都会显著增加。两种寄生蜂均为卵育型寄生蜂。

Female reproductive system and ovary development of two parasitoids of tobacco whitefly

The female reproductive system structures and ovary developmental traits of two parasitoids, Encarsia sophia (Girault & Dodd) and Eretmocerus hayati (Zolnerowich & Rose), of whitefly Bemisia tabaci (Gennadius) were studied to explain the differences of host handling strategies between these two parasitoid species. The female reproductive system of both En. sophia and Er. hayati each consisted of a pair of ovaries and lateral oviducts, common oviduct, spermatheca, ovipositor and ovipositor sheath. The ovipositor of En. sophia is straight and has an apparently hard and sharply pointed upper valve, while that of Er. hayati is curved, thick-walled, but has a blunt and apparently flexible tip. These features correlated well with the oviposition mechanisms of En. sophia and Er. hayati. Significant difference was found in the number of mature ova between En. sophia and Er. hayati when they emerged. The number of mature ova of both parasitoids increased with the age of adult female when the available nutrition was enough. Both En. sophia and Er. hayati are synovigenic.