Mythimna (Leucania) venalba Moore

Leucania venalba Moore, 1867, Proc. zoo1. Soc. Lond., 1867: 48.

Cirphis philippensis Swinhoe, 1917, Ann. Mag. nat. Hist (8)., 19: 336.

Leucania venalba Moore; Calora, 1966: 654; Holloway, 1976:9.

Diagnosis

The forewings are somewhat browner than in loreyi and roseilinea, with CuA in the cell standing out paler but without a distinct pale spot at the discal end. In the male genitalia the cucullus is rather elongate, and the harpe has a distinctive, apically bifid spine arising from the ventral margin of its base.

Biology

Sevastopulo (1945) described the larva. Early instars are initially grey, becoming green when feeding, moving with a slight ‘semi-looper’ motion. The head is honey-colour. There is a broad, double, purple-brown dorsal line, and a broad sublateral of the same colour. The sublateral and ventral area is whitish. Later instars become browner, with minute dark markings on a pale creamy yellow ground-colour. There is a pale dorsal line edged by a dark brown line then, successively, lines of pale purple brown, ground colour, purple-brown, ground colour, a narrow brownish orange stripe edged purplish brown, ground colour, blackish-brown centred with orange-brown, broad white centred with olive brown. The underparts are pale olive brown. The larva has been recorded from various grasses and also rice (Oryza) (Robinson, 1975).

Genitalia: