The Rice Moth
(By Dr. Girish Chandra)
Host: A pest of stored rice, millets and other cereals. Prefers broken grains and flour.
Damage: Caterpillars cause the damage by webbing together grains and forming lump and feed from inside it. Larvae before pupation wander about and leave a lot of webbing in the grains, causing excessive lumping, which reduces marketing quality of the grains.
Life cycle: Adults light greyish-brown in colour, 12 mm long and with a wing span of about 15 mm, without any markings on the wings but veins are slightly darkened. Head bears a projected tuft of scales. Moths are short lived but realise a fecundity of 150—200 eggs per female within a few days after emergence. Eggs are laid anywhere, on the grains, among grains, on the containers or on any surface near the grains, either singly or in clusters. Eggs are whitish, oval in shape, 0.5 mm long and having an incubation period of 4-5 days. Tiny larva after hatching is creamy-white, with a prominent head. It moves about actively and feeds on broken grains for sometime and then starts spinning web to join grains. Full grown larva is pale whitish in colour, 15 mm long with short scattered hairs and no markings on body. Larval period is 25-35 days in summer and may be extended in winter. Pupation takes place inside an extremely tough, opaque whitish cocoon that is surrounded by webbed grains. Pupal period is about 10 days but may extend to 40-50 days to tide over winter moths. Moths commence mating and egg laying immediately after emergence.