Ootaxonomic investigation of the Italian species of the genus Electrogena (Ephemeroptera, Heptageniidae)

Abstract

The egg chorion of the Italian species of the genus Electrogena was investigated using the scanning electron microscope (SEM). The eggs examined showed distinctive chorionic patterns. Electrogena grandiae, E. lateralis and E. zebrata showed attachment structures characterized by knob‐terminated coiled threads (KCTs). These structures were uniformly scattered over the egg surface in E. grandiae, while in E. lateralis they differed in size and position. In E. zebrata, the attachment structures were of uniform size and formed a dense mat over the whole egg surface. In contrast, no specialized sculptures were found in E. fallax and E. gridellii. The different chorionic patterns allowed specific identifications. The affinities and the taxonomic position of the species examined are discussed.