Lophoptera illucida Walker

Stictoptera illucida Walker, 1865, List Specimens lepid. Insects Colln.Br. Mus. 33: 918.

Lophoptera illucida Walker; Holloway, 1976: 19.

Diagnosis

This species is recognised by the dark brown, almost black semicircle at one third on the forewing dorsum; only rarely is this obscured with rufous in Bornean specimens which might lead to confusion with leucostriga (with a much more developed lenticular submarginal) or ferrinalis (with a more elongate rufous zone). The semicircle is often associated with a white patch, slightly distal and anterior to it (illustrated). Other forms, rare in Borneo, have the central zone of the forewing longitudinally paler or a purplish tone to the forewing with pale patches at the tornus and centre of the margin (both illustrated).

Biology

The larva has been described by both Bell (MS) and Gardner (1948 a). The descriptions differ slightly. The following is taken from Bell with Gardner’s observations in square brackets. The larva is cylindrical, narrowing somewhat towards the head. The head is pale yellow [brown] with a black crescent from the antennal bases that curves towards the clypeus. The body is green [yellow], marked variously with dull, dark purple [black], sometimes only in an irregular lateral patch, sometimes extending broadly down the flanks and, at the anterior of each segment, over the dorsum. The first thoracic segment is always pure green above the lateral line and has a narrow black anterior margin. [The legs and prolegs are pale, the latter brownish apically, and the spiracles have fine brown rims.] Bell’s larvae were brought in moulting to the final instar in cells formed by folding young leaves of the host-plant, the folds fixed by regular walls of dense, pure white silk. The larva feeds in the young leaves, often within a loose cell of the same nature. It turns pink prior to pupation which is in the soil in an ovoid cocoon of grey silk coated with earth particles and fitting the pupa closely. The pupation time is about two weeks. Both recorded host-plants are in the Dipterocarpaceae: Shorea robusta (Sevastopulo, 1941; Gardner) and Hopea wightiana (Bell).

Genitalia: