Genus Idiocerus Lewis

Idiocerus Lewis 1834: 47; Viraktamath & Sohi 1994: 23. Type species: Idiocerus stigmaticalis Lewis, by monotypy.

Diagnosis. Anufriev & Emeljanov (1988) diagnosed the genus Idiocerus as follows. Head anteriorly triangular, wider; postclypeus nearly rounded. Lateral margins of face more or less straight. Forewings with 3 subapical cells; outer cell very long. Male antennae with platter; third segment with 3 basal bristles. Subgenital plates comparatively small. Style with 1 large bristle at apex. Apex of aedeagal shaft flattened dorsoventrally, spade-shaped; subapical processes short. Female sternite VII about 2× as wide as long medially, posterior margin more or less convex with median shallow concavity. Valvula I with oblique strigae, sculptured area occupying almost distal half length (Figs 65 EF, IJ). Valvula II with toothed area occupying distal 0.3–0.33 length, teeth prominent and distinctly separed from each other (Figs 65 GH, KL).

Remarks. Dlabola (1973) defined the genus and segregated the taxa which did not belong to this genus. Anufriev & Emeljanov (1988) provided a revised diagnosis of the genus. Here the diagnosis provided by Anufriev & Emeljanov (1988) is followed to place the two Indian species in this genus. The Indian species have following additional features which are not mentioned by Anufriev & Emeljanov (1988) in the diagnosis. The upper part of the face dorsad of ocelli and crown is rugose; the clypellus is either as wide apically as base or wider; the metafemur has 2+0 distal macrosetae; the metatibial chaetotaxy on rows AD 6, PD 6 and AV14; the metabasitarsomere has 3 platellae on distal transverse row flanked by one seta on either side (Figs 17E, 18E).

Two species of the genus are known to occur in the subcontinent and both belong to the nominotypical subgenus.

Key to species of Idiocerus (Idiocerus) Lewis from the Indian subcontinent

1. Male tergal apodemes at base of abdomen well-developed, exceeding third tergum and as long as broad; aedeagus with dorsal apodeme stout, dark pigmented (Fig. 17 IJ); female sternite VII convex with median excavation (Fig. 61A); breeding on Cedrus deodora ................................................................... I. (I.) cedarae Viraktamath & Sohi

- Male tergal apodemes at base of abdomen 2× as broad as long, not reaching posterior margin of third tergite; aedeagus with dorsal apodeme slender less pigmented (Fig. 18 HI); female sternite VII produced medially (Fig. 61D); breeds on Salix sp. ...........................................................................I. (I.) sharmai Viraktamath & Sohi