Achrosis longifurca sp. n.
Achrosis longifurca (holotype)
11-14mm, perhaps on average slightly larger than fulvifusa (11-12mm).
Externally, the only distinguishing feature is the not very reliable one of a
greater intensity towards the tornus of the dark brown fascia on the hindwing
just distal to the discal spot. In fulvifusa this is weaker, of even
intensity. Reliable distinguishing features are found in the male genitalia: the
furca arms are much longer, more slender, almost straight; the ventral margin of
the valve has its greatest curvature centrally rather than subapically, and
meets the produced costal part at the apex more gently rather than angled
sharply in to it, with a shoulder; the gnathus apex is less acute, more rugose;
the uncus is only weakly setose apically rather than strongly so.
Gunong Mulu Nat. Park, R.G.S. Exped. 1977-8 (J.D. Holloway et al.), BM
1978-206, Site 14, February, Camp 2.5, Mulu 1000m 413461, lower montane
forest, BM geometrid slide 10404.
Paratypes. 2(slides 10407, 10408) general data as holotype but Site 8, February,
Camp 1, Mulu, 150m. 585470, mixed dipt. for.; 3 (slides 10411, 10413, 12785)
BRUNEI: 15m, Telisai, sandy heath forest with Gymnostoma, 1979 (Lt.
Col. M.G. Allen). Only dissected material is included in the type series; a
number of other specimens from the same localities are presumed to be this
Geographical range. Borneo.
Habitat preference. Compared to the previous species, this shows a
preference for lowland forests on acid soils (e.g. dry kerangas at Telisai,
Brunei) and lower montane forest..
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