Tamba sidonalis Walker

Zethes sidonalis Swinhoe, 1917, Ann. Mag. nat. Hist. (8), 20: 162.

Diagnosis

The wings are a pale brownish grey with a darker marginal zone and, on the male forewing, a series of darker, rather crenulate fasciae basal to the postmedidal; these are faint in the female. The band immediately distal to the postmedial is palest, and the submarginals distal to this are more evident at the dorsal end, especially on the hindwing. The female from the Barito Ulu (see below) has the postmedials and the forewing antemedial finely black, and CuA in the cell, M3 and CuA1 on the forewing are also finely lined with black.

Taxonomic note

The species is related to T. decolor Walker (Sri Lanka) which has a similar general facies but slight differences in the male genitalia. These are more elongate in sidonalis, though decolorhas an extra triangular process at the costal side of the distal series of processes on the valve.

Geographical range

Peninsular Malaysia, Sumatra, Borneo, Thailand (VK).

Habitat preference

The three specimens seen are from Samarinda and upstream from Pontianak in the lowlands of Kalimantan, and one taken more recently from lowland forest at 60m in the Ulu Belait area of Brunei.

Biology

The long, cylindrical larva of the related decolor Walker was reared by Bell (MS) from Aporusa (Euphorbiaceae) in India. Prolegs on A3 are missing, and those on A4 are vestigial. The head is light yellow with an orange semicircle on the vertex and tinged green or brown elsewhere; the setae are long and dark. The body is very light green with irregularly wavy dorsal, subdorsal, dorsolateral, supra- and subspiracular bands of blackish suffusion with white edging, the blackish suffusion intensifying to the rear of each segment. The spiracles are black. Pupation is on the ground in a white silken cell covered with soil particles.

Genitalia: