Leaf eating caterpillar menace in greengram

All the larval instars feed on the green foliage and defoliate greengram completely and cause more than 50 per cent crop damage.

Among all pulse crops greengram is frequently grown as short duration crop in kharif followed by rabi crops like jowar, wheat, bengalgram and safflower. It is quite a hardy crop grown on residual moisture.

It is drought resistant and suitable for dry land farming. The crop plays an important role in sustaining soil fertility by improving soil physical properties and fixing atmospheric nitrogen.

Low yield

The low yield of greengram in our country may be attributed to a wide variety of factors, among which the ravage of insect pest is paramount. A number of insect pests belonging to different orders have been recorded on greengram from various parts of the world.

Important pests of greengram are cut worm, stemfly, aphids, thrips, Bihar hairy caterpillar, tobacco caterpillar, gram caterpillar, hawk moth or leaf eating caterpillar and pod borer.

These pests occur almost regularly at different stages of the growth and cause heavy damage. Among these, leaf eating caterpillar has gained major pest status on greengram and other pulses in recent years.

All the larval instars feed on the green foliage and defoliate greengram completely and cause more than 50 per cent crop damage.

Individual eggs

Small bright bluish coloured eggs are laid individually on all parts of the plant. The eggs are short ovoid, slightly concave at one end and the surface is smooth and shiny.

The fifth instar larva is very active and feeds voraciously on leaves including veins. Fully grown larvae stop feeding and pupate into the soil. Emergence of the adult usually occurs during night.

— Summer ploughing exposes the pupal stage of the pest to natural predation.

— Hand pick grown up caterpillars during day as they hide in cracks and under the plant during day.

— Spray insecticides like emamectin benzoate 5 SG at 0.25ml/l or spinosad 45 SC at 0.25ml/litre or lambda cyhalothrin 5 EC 1.00ml/litre or chlorpyriphos 20 EC at 2ml/litre for effective management of the pest.

(Dr. D.N. Kambrekar, Scientist,(Agricultural Entomology) and Dr. A. P. Biradar, scientist, Regional Agricultural Research Station, UAS Campus, Bijapur-586 101 (Karnataka), email: kambrekardn@gmail.com Phone: 08352-230568)