Mythimna (Leucania) irregularis Walker

Nonagria irregularis Walker, 1857, List Specimens lepid. Insects Colln Br. Mus., 11: 712.

Leucania coenosa Snellen, 1877, Tijdschr. Ent., 20: 24.

Axylia abstracta Swinhoe, 1890, Trans. ent. Soc. Lond., 1890: 221.

Leucania sepulchralis Lucas, 1900, Proc. Roy. Soc. Queensland, 15: 149.

Craterestra scalata Warren, 1912, Novit. zool, 19: 10, *syn. n.,*

Diagnosis

The dark, grey brown forewings with a paler, lenticular costal zone, and a prominent, pale, discal spot are diagnostic.

Geographical range

Indo-Australian tropics to New Guinea and Queensland.

Habitat preference

Bornean material is limited and without precise locality data. The species has been recorded from G. Kinabalu and G. Marapok.

Biology

Sevastopulo (1948) described the early stages. The almost spherical eggs are laid in small batches within the fold of a blade of grass. Early instars move as a semi-looper. They are brown, green when feeding, with eight longitudinal purple lines. Later instars (there are 6) are green, the colour and pattern formed by minute dots in a pale ground. The penultimate instar has dark green dorsal and subdorsal stripes, below the second of which is a white line, a pale olive stripe, another white line and pale-centred dark green stripe. There is a white spiracular line separated by a brown stripe from another white line below it. The final instar is blackish above, with white median and subdorsal lines. The flanks are striped rufous, green and white. The venter is usually pale greenish grey. Pupation is in the soil in a slight cocoon. The host-plants are grasses.

Genitalia: