Scanning electron microscope observations on the egg chorion of the Uzi fly Exorista bombycis (Louis) (Diptera : Tachinidae) were carried out to obtain further understanding of the probable function and development of chorionic structures of eggs. The study reveals morphologically and physiologically important structures viz. aeropyles, micropyles, a circular lid with a well defined hatching line, a chorionic respiratory network, etc . The egg of E. bombycis is considered indehiscent, i.e., the egg chorion is not modified for hatchin g and the larva emerges from the ventral egg surface. However , a lid surrounded by a well defined hatching line is present in E. bombycis, but is genera lly found in dehiscent Tachinid eggs and is used for hatching. Further, the type of chorionic respiratory systems in the family Tachinidae are discussed in detail.
Eggshell, Chorionic respiratory system, Hatching line, Uzi fly, Scanning electron microscope
