Oogenesis of Nicoletia phytophila ( Zygentoma , Nicoletiidae ) . Preliminary Studies

Zygentoma and Microcoryphia, which used to be combined in one order Thysanura, are Apterygota most closely related to Pterygota. As histological and ultrastructural studies have shown, both Zygentoma and Microcoryphia have panoistic ovaries (Bitsch, 1980a, b; Bitsch and Bitsch, 1982). Vitellogenesis, of heterosynthetic or mixed type with heterosynthetic kind dominating, is typical of these insects (Bitsch, 1980b; Bitsch and Bitsch, 1982). Nicoletia phytophila is a representative of Zygentoma of the family Nicoletiidae. Oogenesis has not yet been studied in this family and seems to be worth a closer examination, because of the unusual life style of this species (see Material and Methods). Besides of it, the analysis of the oogenesis of N. phytophila might lead to interesting phylogenetic conclusions. This is all more likely, since studies of oogenesis are a good basis for consideration of the relationships of groups of insects and other invertebrates (Eckelbarger, 1983).