棉铃虫卵巢形态与卵子发生过程观察

Observation on ovarian morphology and oogenesis in the cotton bollworm, Helicoverpa armigera (Lepidoptera: Noctuidae)

害虫发生高峰期、发生量的准确预测和田间防治适期的确定与种群雌虫卵巢结构及卵子发生过程密切相关。为了明确棉铃虫Helicoverpa armigera卵巢结构及卵子发生过程,本研究利用光学体视显微镜和透射电子显微镜,对棉铃虫成虫卵巢管和卵子的超微结构进行了研究,并确定了发育级别划分标准。结果表明:根据卵巢的形状、卵的产生过程、卵黄沉积情况等将棉铃虫卵巢发育程度分为6个级别,即发育初期(0级)、卵黄沉积前期(Ⅰ级)、卵黄沉积期(Ⅱ级)、成熟待产期(Ⅲ级)、产卵盛期(Ⅳ级)和产卵末期(Ⅴ级)。根据卵子发生过程中滋养细胞、卵母细胞的变化,将卵子发生期分为3个阶段:卵黄发生前期、卵黄发生期和卵黄成熟期。本研究首次对棉铃虫的卵子发生进行电子显微观察,并完善了棉铃虫卵巢发育的分级标准,为进一步研究棉铃虫的生殖发育机理提供了理论参考,对田间棉铃虫种群发生期和发生量的预测预报也有重要的实践参考价值。

The ovarian structure as well as oogenesis is closely related with the accurate forecast of the pest occurrence peak and the appropriate control time. In order to make sense of the ovarian structure and oogenesis in the cotton bollworm, Helicoverpa armigera, we investigated both the ovarian structure and oogenesis of H. armigera female moth under the light microscopy and transmission electron microscopy, and determine the grading criteria to divide different developmental stages. According to the morphological characteristics of ovaries, the formation of eggs in the lateral oviducts and the characteristics of yolk deposition, the H. armigera ovaries are graded into 6 stages, including stage 0 （the initial stage）, stage Ⅰ （yolk deposition prophase）, stage Ⅱ （yolk deposition phase）, stage Ⅲ （egg maturation phase）, stage Ⅳ （peak phase of oviposition） and stage V （terminal phase of oviposition）. According to the ultra-structural change of the oocytes and follicular cells, the developmental period of oogenesis is divided into 3 stages： the vitellogenesis prophase, vitellogenesis stage and yolk maturation stage. This study is the first research about oogenesis of H. armigera using electron microscopy, which optimizes the grading criteria of ovarian development of the cotton bollworm. The result provides an important theoretical basis for further study of reproductive development of H. armigera, and also has important practical meaning for the accurate forecast of outbreak date and scale in pest management.