Ligidia Walker

Type species: decisissima Walker.

This is a monobasic genus represented by only the holotype male of the type species. Nye (1975) referred to it as lectotype but no other  specimen has been located.

Hampson (1910) illustrated features of the head and wing venation, and noted that the tongue was reduced. The labial palps are porrect, the second segment reaching the centre of the frons and being tufted distally on the dorsal side; the third segment is short. The frons is also tufted. The forewing radial sector venation is unusual, with (R1, R2) stalked independently from ((R3, R4) R5). The wings are worn, pale brownish fawn, virtually unmarked apart from some black marginal dashes in the spaces between the veins.

The male abdomen has the eighth segment flimsy but of the framed corematous type. Phragma lobes on T2 are absent, but the basal abdominal tergites have an unusual frame-like structure as illustrated. The genitalia have a slender uncus that is apically acute; there is scaphial thickening on the anal tube. The tegumen is long relative to the rather broad vinculum, and its sides have distinct ‘lapels’ on the interior margins. The valves are acute, tapering, with two blade-like processes subapically.

A very closely related monobasic genus, Tesomonoda Nye (= Odontosema Warren, praeocc.), occurs in New Guinea. The type species is endolopha Hampson and was originally described in Ligidia. The male abdomen has a similar frame-like thickening in the basal abdominal tergites and similar ‘lapels’ to the tegumen of the genitalia. The valves are also similarly ornamented, but the cucullus extends further beyond the costal processes and is paddle-like, apically rounded. The female genitalia have a broad antrum and ductus bursae leading into a weakly pyriform corpus bursae. There is a sclerotised, slightly sigmoid appendix bursae arising from the centre of the corpus bursae and directed posteriorly.

When more material of decisissima is available, it may prove that separation of the two genera is unjustifiable.