::The Moths of Borneo::

Type species: dahlii Hubner, Palaearctic.

Synonym: Oxira Walker (type species ochracea Walker).

Diarsia is a large Holarctic genus with a centre of diversity in the montane regions of western China (Boursin, 1954-1963). As with other noctuine genera, it is best defined on characters of the male genitalia: the valve is constricted subapically such that the corona is set on a definite cucullus; the upper process of the harpe, probably homologous to that of Xestia and Agrotis in that it is rooted in the sacculus by a wedge of sclerotisation, is directed dorsally (overlapping the costa) and overlies a second process that extends distally and ventrally to beyond the ventral margin; the aedeagus vesica is short, often globular, usually with some scobinate spinose patches, with a coarsely spined sclerotised band extending into it from the aedeagus apex. In the female genitalia the ductus bursae is small. The bursa has short signa bands in some species, usually transverse; the ductus bursae is fluted, scobinate.

The larvae are again polyphagous defoliators of mainly herbaceous plants.

The South-east Asian and Australasian species fall into two main groups with a number of morphologically more isolated species mostly endemic to G. Kinabalu in Borneo. All are montane.

The first group has filiform antennae in the male as do the majority of taxa, but the male genitalia share a number of features: the sacculus extends well beyond the relatively basal double harpe and curves round just subapically to form a notch with the cucullus rather than curving evenly into it; distal to the harpe on the sacculus is an elongate setose zone; the uncus is set on distinct shoulders on the tegumen; the aedeagus vesica has an irregular basal zone clad densely with moderate, slender spicules, and is itself globular in all taxa from Sulawesi eastwards (thus indicating a possible natural subgroup). There are two species in Borneo, nigrosigna Moore and flavostigma Holloway, and further species, including a large Australasian complex, as follows:

Diarsia dimorpha Wileman & West comb. n.	Luzon
Diarsia sp. (slide 12975)	Java, Bali
Diarsia sp. (slide 12934)	Sulawesi
Diarsia melanomma Prout comb.n.	Buru
Diarsia olivacea Prout comb. n.	Seram
Diarsia pallidisigna Prout comb. n.	Buru
Diarsia pallidimargo Prout comb. n.	Seram
Diarsia sp. (slide 12940)	Seram
Diarsia sp. (slide 14083)	New Guinea
Diarsia pediciliata Prout comb. n.	New Guinea, Seram
Diarsia kebeae Bethune-Baker comb. n.	New Guinea, ?Seram
Diarsia stigmatias Prout comb. n.	New Guinea
Diarsia owgarra Bethune-Baker comb. n.	New Guinea
Diarsia intermixta Guenee	Australia, Norfolk I. New Zealand

In addition there are several more undescribed species from New Guinea in the BMNH and probably amongst the material in the Australian National Insect Collection, Canberra, collected by W.W. Brandt. The genus reaches its most easterly point in the Solomons where an undescribed species flies on Mt. Popomanaseu, Guadalcanal.

The second group, defined by presence of strongly bipectinate antennae in the male, unusual amongst Noctuinae, extends from India to Seram and includes the Sri Lankan type species of Oxira Walker, ochracea Walker. There are two species in Borneo, borneochracea sp. n. and stictica Poujade, and the following further species, all except the last two being closely allied to ochracea:

Diarsia gaudens Hampson comb. n.	Java, Sumatra
(= pygmaea Boursin)	Java, Sumatra
Diarsia sp. (slide 12964)	Peninsular Malaysia
Diarsia sp. (slide 12961)	Java
Diarsia magnisigna Prout comb. n.	Seram, Sulawesi,
(angusta Prout syn. n.)	Java and Bali (slide 12962)
Diarsia sp. (slide 13927)	Sulawesi

The remaining three Bornean species are the Kinabalu endemics. To them may be added a high altitude endemic from G. Kerinci, Sumatra, namely D. inconsequens Rothschild comb. n. One further Himalayan species, D. albipennis Butler, has been recorded from the Cameron Highlands of Peninsular Malaysia by Dr G.S. Robinson and has been taken in Sumatra by Dr E. Diehl.