On the mechanism of copulation in Hepialid moths, Endoclita excrescens (Butler) and Hepialus fusconebulosa (De Geer) (Lepidoptera: Hepialidae)

Abstract

The male and female genitalia of Endoclita excrescens (Butler) and Hepialus fusconebulosa (De Geer) are described and figured. The musculature of male genitalia of Endoclita excrescens (Butler) is described and figured. The mode of firm connection between male and female genitalia, which has not been recorded in Lepidoptera, is effected in the following sequences: (1) the mesosome was inserted into the dorsal groove of central process (E. excrescens) or grappled the dorsal sclerotized portion of central process (H. fusconebulosa), (2) the valvellae were applied to the lateral walls of seminal gutter (E. excrescens) or the depression of subanal plate (H. fusconebulosa), which was opened by the inflation oftegumen, (3) the valvae clasped the weakly sclerotized portions of female diaphragma (E. excrescens) or lateral portions of female ninth tergum and sternum (H. fusconebulosa). The characteristics of these copulation mechanism in Hepialidae and their phylogenetic significance are shortly discussed.