Biological investigations on Lymantria obfuscata (Walker): A major insect pest on walnut (Juglans regia L.) trees in Kashmir

Among vast array of insect pests damaging the walnut trees, a serious and destructive lepidopteron insect pest has been reported Lymantria obfuscata (Lepidoptera: Lymantritiidae) causing an extensive damage to walnut plantations in Kashmir. The present study was conducted because the walnut has high medicinal, nutritive and economic value. It earns the J & K state large annual revenue and JK state's walnut contribution makes the 98% of total walnut production of our country. The egg undergoes overwintering from last week of July to the month of March when hatching take place. The pest passes through five larval instars and fifth instar undergoes pupation in the crevice or under the bark of host followed by the adult emergence in the month of June. The female lays eggs near its pupation site because of its larger body size due stored egg mass. The larvae show the phenomenon of ballooning. Under severe infestation larvae cause complete defoliation of the walnut trees that result in decrease in size of fruits, fruit yield and vigour of the trees. The ongoing threat of the further spread of it requires a region wide campaign to be launched.