Chadisra borneensis sp. n.
23-24 mm. The facies
is similar to that of basivacua but the exterior half of the forewing is
less green, the interior half darker, the zone between the ‘step’ and the
dorsum being pale fawn, the palest part of the forewing. The genitalia are very
distinctive with broad triangular gnathal processes, transtillae that are deep,
fused across the centre and bearing a pair of massive spines, valves with a thin
dorsal triangular portion and a heavily sclerotised, squarish ventral portion,
and a juxta extending dorsally in a long sclerotised strap, spined at the tip
(detached and still associated with the aedeagus in the illustration). The
Nepalese male mentioned earlier that is probably attributable to bipars or
albobrunnea has the same broad tegumen and plate-like gnathal processes,
but the latter are tridentate; the transtillal band has a central bifurcate
process rather than two lateral ones; the juxta is similarly straplike but not
apically scobinate; the valves have in addition a large, central, apically
scobinate ampulla; the eighth tergite is similarly broadly and deeply bilobed
but the stemite is trilobed rather than entire (an obtuse angle), with widely
spaced lateral pouches centrally instead of two more closely adjacent subapical
30 mm, resembling a large grey form of luzonensis but with the
hindwing heavily suffused with dark grey. The genitalia are massive with a broad
lobe followed by a pair of lobes posterior to the broad, membraneous ostium
bursae. The two Himalayan taxa mentioned above also have short, unornamented
bursae set in a broad complex array of folds and sclerotisations of the terminal
sternites, though differing in detail; this is support for the contention that
the Nepalese male is referable to one or other of them.
Holotype BRUNEI: 1618 m, Bukit Retak, montane forest, 25.4.81 (Lt. Col. M. G.
Allen) BM notodontid slide 1101.
Paratypes. 1 as holotype, BM notodontid slide 1111; 1 BRUNEI: 30 - 60 m, Labi (Lt.
Col. M. G. Allen); 2 SARAWAK: Gunong Mulu Nat. Park, R. G. S. Exped 1977-8 (J.D.
Holloway et al.), Site 20, 150 m, kerangas, W. Melinau Gorge, and Site 23,
250 m, forest on limestone, W. Melinau Gorge.
Geographical range. Borneo.
Habitat preference. The few records have been from several types of
lowland rain forest and from upper montane forest.
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