Ovarian Structure and Oogenesis of the Webspinner Oligotoma japonica (Embioptera, Oligotomidae)

Ovarian structure and oogenesis of the webspinner Oligotoma japonica OKAJIMA are described by using light microscopy. The ovary consists of 5 pairs of panoistic ovarioles connecting with each lateral oviduct regularly arranged. The ovarial ligament of each ovarioles is attached to the dorsal blood vessel. An ovariole contains a linear array of 8 developing oocytes in different stages. Anterior 5 oocytes (1-5) show previtellogenic slow growth (stage 1). The fatty yolk globules appear in the ooplasm of the 6th oocyte (stage 2). In the 7th oocyte, the deposition of proteid yolk begins within the cortical and subcortical ooplasm (stage 3). Fully grown or the 8th oocyte is at the posterior end of the ovariole, and the vitelline membrane and chorion are produced on the oocyte surface by surrounding follicular cells (stages 4-5).