View Image Gallery of Tribe Nygmiini n.

Arna Walker Gen. rev.

Type species: apicalis Walker, Sri Lanka.

This genus is best defined on male genitalia characters, though many species have a bipunctate forewing apex. The forewing venation lacks an areole and has R2 branching off more distally than R5. M1 is connate or slightly stalked with Rs. In the hindwing both M1+Rs and M3+CuA1 are stalked.

The male abdomen has tymbals. The eighth tergite is triangular or bilobed, the projections becoming a fringe of scales. The uncus is diagnostically long, broad, apically divided in the dorsoventral plane, and the whole rather triangular structure is flexed down posteriorly over the central part of the genitalia. The valves are simple, set somewhat ventrally, usually narrowing towards the apex. The saccus is narrow, triangular. The aedeagus is small, slender.

In the female, the terminal segments together up to the membrane between the eighth and seventh are short, compact, the eighth a simple ring. The ostium, ductus and bursa are narrow, the latter flimsy, lacking a signum. The characteristics of the ostium can be diagnostic as seen below.

The biology of one of the Bornean species is described below. Moore (1883) described and illustrated the larva of the type species. It is olivaceous green, with a broad dorsal reddish band enclosing a thin dorsal black line. There are dorsal tubercles on A1, A2 and A8. The head is reddish. The host-plant was Terminalia (Combretaceae).

The limits of the genus are as yet unclear, but it appears to be restricted to the Oriental Region. The genus also includes A. phaulida Collenette comb. n. (India) and A. flavolimbatulana Strand comb. n. (Java).

<<Back >>Forward <<Return to Contents page

Copyright Southdene Sdn. Bhd. All rights reserved.