FIRST REPORT OF YELLOW TAIL TUSSOCK MOTH, SOMENA SCINTILLANS WALKER (LEPIDOPTERA: LYMANTRIIDAE) ON APPLE PLANTATIONS IN JAMMU

Abstract

Apple (Malus domestica) is a small deciduous tree belonging to the family Rosaceae is one of the most widely cultivated tree fruits. It is originated from Western Asia, where its wild ancestor, Malus sieversii, is still found today. Many beneficial health effects have been found from eating apples, however, the seeds are slightly poisonous and two forms of allergies are seen to various proteins found in the fruit. During regular surveys in the apple orchards, the leaves of apple plantations were found damaged heavily by the larvae of Somena scintillans Walker. The caterpillars are voracious feeders and in severe cases of infestation, the entire trees may be defoliated. Earlier the pest has been recorded from Assam, Gujrat and Himachal Pradesh. Presently, authors have reported this pest from all apple growing regions of Jammu province for the first time and this study was to obtain information on the biology of S. scintillans walker under laboratory conditions. Biology of this pest was studied on red delicious cultivar of apple under laboratory conditions from June to December, 2008 and again during 2009 Jammu province. The larvae were collected from the infested apple orchards and reared in cages on apple leaves and were kept in laboratory to record observations on its life stages. After pupation, pupae were kept separately in Petri dishes (10 cm dia) for recording pupal duration. Fully developed larvae, pupae and adults were measured. The male and female moths after emergence were kept in pairs in wire mesh cages lined with filter paper for mating and egg laying. The egg masses were carefully dehaired and number of eggs per female was counted. The incidence of the pest was observed in the field from mid of June and remained active from July to November. After November the insect disappeared due to sudden decrease in temperature. Adult moths start mating 4-5 hrs after emergence as observed in the laboratory after sunset. Mating was preceded by courtship, where males fly and chase the females. During the act of copulation, females keep their wings expanded and abdomen little raised to facilitate easy copulation. Females laid eggs (10-209 eggs) in clusters on the lower surface of the leaves (Plate 1a). Eggs round were 0.43±0.01 (N=20; SE=0.002) mm in diameter, pale yellowish, laid in clusters. Females deposited eggs only once in a single go. Incubation period varied from 7-10 days with an average of 8.65±0.28 days. Prior to hatching, the eggs changed their colour become brownish. When ready for hatching, the larva started eating the egg shell and thereby making a hole at the top of the egg shell which is used as emergence hole by the larva during eclosion. Hatching takes place during night and day hours but maximum hatching occurs during