Ovary of Matsucoccus pini (Insecta, Hemiptera, Coccinea: Matsucoccidae): morphology, ultrastructure, and phylogenetic...

The structure of ovary in a representative of the scale insect family Matsucoccidae, Matsucoccus pini, is described at the ultrastructural level. The paired ovaries of M. pini are composed of about 50 ovarioles of telotrophic type that develop asynchronously. An individual ovariole consists of an anterior tropharium (trophic chamber) and posterior vitellarium. The tropharium encloses trophocytes (nurse cells) and early previtellogenic oocytes termed arrested oocytes. In the vitellarium from 1 to 6, linearly arranged oocytes may develop. Analysis of serial sections has shown that each ovariole contains 32 germ cells (trophocytes, arrested oocytes, and developing oocytes). In the cytoplasm of all these cells, small rod-shaped bacteria are present. In the early vitellogenic oocytes, accessory nuclei arise. As vitellogenesis progresses, these nuclei migrate toward the cortical ooplasm. The obtained results are discussed in a phylogenetic context.