Structure of ovaries in scale insects. I. Pseudococcidae, Kermesidae, Eriococcidae, and Cryptococcidae (Insecta, Hemiptera, Coccinea)

摘要

Developing ovaries of the scale insects Nipaecoccus nipae and Cryptococcus fagisuga contain clusters of interconnected cells (cystocytes) that are arranged into rosettes; polyfusomes occur in the centres of the rosettes. Ovaries of the adults of these scale insects are composed of numerous short telotrophic ovarioles. Tropharia (trophic chambers) of Dysmicoccus newsteadi, Eriococcus buxi, C. fagisuga and Pseudochermes fraxini comprise only trophocytes (nurse cells), whereas those of Kermes quercusand Gossyparia spuria also contain arrested oocytes. The latter probably degenerate. It is suggested that during evolution of scale insects a gradual reduction of germ cells to 4 per cluster (3 trophocytes and 1 oocyte) took place. In light of the obtained results, anagenesis of scale insect ovarioles is discussed.