Revision of the genus Ogygioses (Palaeosetidae)

Abstract

The systematics and external morphology of the oriental genus Ogygioses are reviewed. Monophyly of the genus is demonstrated by the two segmented labial palpi, loss of the jugal lobe in the forewing, stalking of the forewing R4 with the base of R2 + 3 and a specialised scale arrangement on the forewing base. Sculpturing of the egg chorion differs from that of other Exoporia in exhibiting elongate tubercles regularly dispersed over the surface. The genus is retained tentatively in the Paleosetidae on the basis of the loss of all tibia1 spurs, including the epiphysis, and the extreme reduction of the maxillae. Four species are recognised: O. caliginosa Issiki & Stringer, O. eurata Issiki & Stringer, O. issikii Davis, sp. nov., from Taiwan, and O luangensis Kristensen, sp. nov., from Thailand. Adults are diurnal with the males forming hovering groups, or leks, similar to some species of Hepialidae.