Idaea ?sakuraii Inoue

Sterrha sakuraii Inoue, 1963, Tinea, 6: 30.

Diagnosis

This species is greyer than ptyonopoda and more strongly fasciated, the postmedials being slightly enlarged, dark brown, where they meet the wing margins.

There is a diffuse, broad hindwing medial.

The scent-pencils of the male hind-tibia are medium brown.

The male genitalia are distinguished by a pair of spined processes that flank the aedeagus.

The female typically (Japan, Hong Kong) has a large, horseshoe-shaped sclerotisation on the lamella antevaginalis, surrounding the ostium.

Taxonomic Notes

Identification as sakuraii is tentative, based on the presence of the pair of spined processes.

These vary considerably in specimens examined, being slender in typical Japanese material, robust and like a bird’s head in the Bornean male and more elongate and bidentate in a male from Java.

In males from Hong Kong they are longer with a larger distal spine.

The development of the bulge on the centre of the valve costa is also variable, and not evident in typical Japanese material.

Geographical range

Japan, Hong Kong, Borneo; Java (slide 18585).

Habitat preference

A single male was taken in upper montane forest at 1790m on G. Mulu.

Biology

The larva of sakuraii in Japan is illustrated in Sugi (1987). It is stick-like rather rugose, the rugosity tending to ring each segment in a series of folds: there is a slight lateral longitudinal flange.

The colour is longitudinally streaked pale brown above, pale-speckled indigo below, separated by diffuse pale patches laterally.

There is a paler dorsal line on the thoracic segment.

No specific host-plant was mentioned.