Miscellaneous Genera VI
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Rhesala imparata Walker 
Rhesala imparata Walker, 1858, List Specimens lepid. Insects Colln Br. Mus., 15: 1777.
Homoptera diminutiva Walker, 1865, List Specimens lepid. Insects Colln Br. Mus., 33: 890.
Egnasia erebina Butler 1879, Ann. Mag. nat. Hist. (5), 4: 450, see below].
Heterogramma nigricans Snellen, 1880, Tijdschr. Ent., 23: 136, see below].
Hingula albolunata Moore, 1882, Descr. new Indian lepid. Insects Colln W.S. Atkinson: 181, see below].
Hingula cervina Moore, 1882, Descr. new Indian lepid. Insects Colln W.S. Atkinson: 181, see below].
Raparna costiplaga Holland, 1900, Novit. zool., 7: 592, see below].
Metacausta punctilinea Wileman, 1916, Entomologist, 49: 180, see below].


Rhesala imparata

Diagnosis. The species is much larger than nigricans Snellen but slightly smaller than the two new Bornean species, both of which have a dark bar on the forewing costa, associated with the postmedial. The identity of all four species is best confirmed from genitalia characters. Males of imparata have an elongate uncus with a slight crest of hairs. The valves are tongue-like, with a distinct, but short saccular portion that protrudes as a slight tooth on the ventral margin. The aedeagus vesica is somewhat reflexed, with exterior patches of spines at one third and broadly over the apical third. The female has the basal third of the corpus bursae sclerotised, convolute, with the distal two-thirds spined.

Taxonomic note. Poole (1989) and Nielsen et al. (1996) listed numerous synonyms for imparata. Dissection of the type material has revealed that: erebina Butler (slide 18663; Japan) is a synonym of moestalis Walker, syn. n.; R. albolunata Moore (Nilgiri syntype female, BMNH; slide 18670) stat. rev. and R. cervina Moore (Manipuri syntype female, BMNH; slide 18666) stat. rev. are distinct from imparata and from each other and are best treated as good species for the present; the holotype female of punctilinea Wileman (Taiwan) has lost its abdomen but resembles the albolunata syntype in the course and intensity of its fasciation; the type material of diminutiva Walker (locality not known) is noted as lost in BMNH and is therefore best retained as a synonym of imparata; nigricans Snellen (Sulawesi, RMNH Leiden) is also distinct, as discussed next; the type material of costiplaga Holland (Buru; Carnegie Mus, Pittsburgh) has not been examined, but will probably prove to apply to related but distinct species east of Sulawesi (e.g. New Guinea, slide 18665; see also Holloway (1979)). The geographical range is based only on dissected material.

Geographical range. Sri Lanka (holotype; slide 10150); N.E. Himalaya (Khasis; slide 18664), Singapore (slides 10147, 10151), Borneo (slides 10761, 18789).

Habitat preference. Three specimens have been recorded in recent surveys: from 70m in alluvial forest near G. Mulu; from lowland forest at 100m in the lower Temburong valley; from the coast at Seria.

Biology. Bell (MS) reared a larva in India that he attributed to imparata. The prolegs are long, except the pair on A3 is absent, and the anal claspers are splayed out behind. The body is cylindrical, slightly wider centrally. The head is a shining light orange, the setae long, brown. The body is dull, wrinkled, a plain watery grass-green. Gardner (1941, 1947) described a similar larva except the head was stated to be dark brown with a pale frons and adfrons. The larvae are active semi-loopers, but retiring, living in untidy webbing amongst leaves, feeding on young foliage and shoots. Pupation is in a close, ovoid cocoon of silk and particles of detritus on the soil; the silk can be balled in places in the lining of the cocoon. The pupa does not have a powdery bloom.

The host plants listed by Robinson et al. (2001) are all Leguminosae: Acacia, Albizia, Delonix, Tamarindus. A definite (unpublished IIE) host record from Singapore for imparata is of Samanea (Leguminosae).

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