For successful cultivation of summer moong, proper identification of insect pests, knowledge about their damage symptoms and appropriate management methods is necessary.
Tobacco caterpillar is a polyphagous pest that damages summer moong. The small larvae are black whereas grown up larvae are dark green with black triangular spots on body. Its moth lays eggs in masses covered with brown hairs on the lower side of leaves. After hatching, first and second instar (younger) larvae feed gregariously on the underside of leaves and skeletonise the foliage. Later on, the grown up larvae disperse and feed singly. Besides leaves they also damage buds, flowers and pods. For proper management of this insect pest, it is important to follow integrated control methods given below:
• Cultural Control: Ensure timely sowing of the crop i.e. 20 March to 10 April. Control the weeds, particularly itsit/chapatti as it acts as an alternate host for the tobacco caterpillar.
• Mechanical Control: Egg masses and young larvae of tobacco caterpillar feeding gregariously should be collected along with leaves and destroyed. This is the easiest, cheapest and effective means of managing the pest.
• Chemical Control: It can be controlled by spraying 150 ml of Rimon 10 EC (novaluron) or 800 g of Asataf 75 SP (acephate) or 1.5 litres of Dursban 20 EC (chlorpyriphos) using 100 litres of water per acre with manually operated knapsack sprayer. Spray the crop as soon as the pest appears in the field and repeat after 10 days, if necessary. In case, there is incidence of pod borer Helicoverpa along with tobacco caterpillar, the crop can be sprayed with Kingdoxa 14.5 SC (indoxacarb) @ 200 ml per acre.