Structure and ultrastructure of the egg capsule of Thermobia domestica (Packard) (Insecta, Zygentoma)

Abstract

Eggs of Thermobia domestica (Packard) were collected from a laboratory culture. They were prepared for analysis in light and electron microscopes (TEM, SEM). A few hours after oviposition the egg capsule starts to tarnish and changes its colour to brown. Polygonic shapes on its surface can be seen. The egg capsule consists of a thin vitelline envelope and the chorion. The chorion consists of a one-layered endochorion and a three-layered exochorion. There are minor and major mushroom-like structures placed on the surface of the chorion. Their function is proposed. One micropyle is observed on the anterior pole of the egg. The micropylar opening is formed on the process of a follicular cell.