Gymnoscelis pseudotibialis sp. n.
7-8mm. This species belongs to a complex of very similar brown species
with strong fasciation, the postmedials usually at least shallowly biangular.
Included are lophopus Turner (Queensland, New Guinea), mesophoena Turner
(Queensland), pyrissous Prout (Sumbawa) and tibialis Moore. They
are best distinguished on genitalic features, particularly the cornuti in the
aedeagus vesica and the modification, probably corresponding to the character of
the cornuti, of the ductus and basal part of the bursa of the female. The degree
of spining in the distal part of the bursa also varies. In pseudotibialis the
octavals are strong, with prominent apodemes, more so than in tibialis, but
not as long as in lophopus where the octavals are very slender. The
saccular zone of the valve is expanded, angular as in tibialis, but the
saccus is shorter and the octavals less bowed, and not doubled except apically.
The aedeagus has a row of moderate, more or less straight cornuti in the vesica.
G. tibialis has a single, curved one and lophopus a single
straight one. The ductus in the female has a convolute zone that distinguishes
it from the other species.
Holotype . SABAH: Mt Kinabalu, Park H.Q., 5500ft 23-24.1.1976, (E.W. Classey), BM
geometrid slide 18937.
Paratypes: 1 (slide 19054) NORD BORNEO: Mont Kina Balu, 5.8.1903 (John
Waterstradt); 1 (slide 18970) SARAWAK: Gunung Mulu Nat. Park, R.G.S. Exped.
1977-8 (J.D. Holloway et al.) Site 25, April, G. Api, 900m, 427550
lower montane forest.
Geographical range. Borneo, Peninsular Malaysia, (slide 19072),
Habitat preference. All Bornean material is from montane localities.
Biology. Yunus & Ho (1980) noted tibialis as feeding on Mangifera (Anacardiaceae)
and Hevea (Euphorbiaceae) flowers. Vouchers located in BMNH of both
confirmed the first record as being for tibialis but the second (slide
19090) proved to be pseudotibialis.
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