Tensha postobscura Holloway sp. n.

♂♂ 21-23 mm, ♀♀30 mm.

The facies is as illustrated.

The gradation of reddish brown more darkly towards the dorsum is much more extensive than in the only congener, T. striatella Matsumura (Taiwan). The hindwing is pale brown instead of dark greyish brown.

The curve to the forewing margin and dorsum (which distinguishes the species from Bornean Ambadra) is more even, with no trace of the tornal angle seen in some striatella specimens.

The male genitalia share the bizarre modification of the uncus that distinguishes *striatella,*but differ in having the dorsal crest very broadly bifid rather than slightly bifid, with a third spine just basal to the forked process; the aedeagus has a diagnostic ventral ‘heel’; the pair of spines on the roundly hexagonal eighth sternite extend further to its centre, are closer together and are more heavily sclerotised.

Holotype ♂

SARAWAK: Gunong Mulu Nat. Park, R.G.S. Exped. 1977-8 (J.D. Holloway et al.), BM 1978-206, site 2, January, Camp 4, Mulu, 1790 m, 452463 [Upper montane forest, tall facies] BM notodontid slide 525.

Paratype

• 5♂♂, 1♀ BRUNEI, Bukit Retak, 1618 m (Allen)
• 1♀ BRUNEI, Bukit Pagon, 1670 m (Allen).

Taxonomic Notes

The modification in uncus structure is seen also to a lesser extent in HypambadraKiriakoff (Holloway 1982a), and there may be a case, therefore, for uniting that genus with Tensha.

Geographical range

Borneo, ?Sumatra (Bender & Dierl (1977) recorded striatella).

Habitat preference

All records are from upper montane forest.

Genitalia: