Phalera styx sp. n.
25-27 mm. The forewings are very dark blackish grey with a slightly
paler subapical patch as illustrated; curved double postmedial and darker
subbasal fasciae are faintly visible as are several fine, acutely zig-zig lines
medially. The hindwings are almost black. The species forms a related trio with P.
melantata West comb. rev. from Luzon and P. erconvalda Schaus
n. from Mindanao. In the Philippines species the forewings are apically much
more acute, the margins less rounded, and the markings, especially the pale
subapical patch, more obscure. In the male genitalia of styx the uncus is
twice as deep as in melantata, the gnathal processes massive, mandibulate,
rather than more slender, planar, bifid; the valves are longer, triangular
rather than oval, with the subapical processes more developed. In erconvalda the
gnathal processes are similar to those of melantata but the valve is half
as deep again and the uncus twice as deep.
Holotype .BRUNEI: 30 - 60 m,
lowland forest and secondary vegetation, 12.4.81 (Lt. Col. M.G. Allen), BM
notodontid slide 974.
Paratypes: 5 BRUNEI (Lt. Col. M.
G. Allen), various localities; 6 SARAWAK:
Gunung Mulu Nat. Park, R.G.S. Exped. 1977 - 8 (J.D. Holloway et al.), various
Taxonomic note. The trio of species mentioned above, P. banksi (below) and its
sister-species P. mangholda Schaus comb. n. from Mindanao all have
similar facies and genitalia characteristics, especially the massive broad
rounded uncus that does not extend beyond the equally massive gnathal processes.
The forewing pattern is otherwise of the general Phalera type as are the
genitalia characters. Kiriakoff (1968: 220) placed both the Schaus species in a
distinct genus, Erconholda Kiriakoff. For the reasons given above, Erconholda
is here placed as a subgenus of Phalera stat. n., and is defined by
the facies and uncus characters mentioned. The five species included form an
interesting localised group associating Sundaland with the Philippines.
Geographical range. Borneo.
Habitat preference. The majority of specimens have been taken in rich
lowland dipterocarp forest, and were especially abundant in a sample made during
the Mulu survey; on the bank of a river terrace rising up from alluvial forest
to kerangas near the Melinau Gorge.
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