The larvae feed on the leaves

RED HAIRY caterpillar, Amsacta albistriga, is a serious pest of rainfed groundnut. In South Tamil Nadu its outbreak occurs during September- October.

Damage symptoms

The larvae feed voraciously on leaves leaving the main stem alone. Severely damaged crop presents the appearance of having been grazed by cattle.The adults are medium sized and emerge from their earthen cells in the soil after the monsoon. The moths mate and commence oviposition on the same day. Egg laying lasts for 2 to 6 days.

Creamy eggs

Eggs are creamy or bright yellow and are laid in groups, mostly on the under surface of the leaves and occasionally on other vegetation, clods of earth, stones or dry twigs.A female lays about 600 to 700 eggs. The incubation period lasts for 2 to 3 days. The larvae attain maturity in 40-50 days. Mature larvae are 5cm long, reddish brown with black bands on either end and have long reddish brown hairs all over the body. The larvae pupate along field bunds and in moist and shady places where they undergo pupal diapause under the soil till the next season.

Control measures

- Hand picking and destroying the pupae after summer ploughing.- Setting up of light trap or bonfires immediately after monsoon to attract and kill the moths.- Manually collecting and destroying egg masses and larvae.- If possible dig a trench around the field to avoid infiltration of the caterpillar.- Release of Trichogramma egg parasites two times at the rate of 20,000 per acre.

M. RAJENDRAN,
V.G. MATHIRAJAN &
W.BABY RANI

Regional Research Station, Aruppukottai, Tamil Nadu