Enigmatic tube-web construction by Gorgopis Hübner ghost moth larvae in South Africa (Lepidoptera: Hepialidae)

A partially damaged male imago reared from a larva feeding on Eragrostis curvula (Poaceae) was identified as a species of Gorgopis. Adult and immature stages of the reared specimen are illustrated. The larva lives within a tunnel in the soil. At the ground surface, the tunnel extends above ground as a tube of grass stalk fragments cut by the larva and bound together by silk. These feeding tubes are found at the base of grass tussocks, principally among the dense accumulation of dead stalks. It is not known if the larvae feed on dead or live grass foliage, or a combination. The feeding tube is the second mode of larval feeding documented for ground dwelling southern African Hepialidae, the other being 'silk purser' feeding webs of unknown taxonomic status. The lectotype for Gorgopis libania Cramer, 1781 is here designated.