BIOLOGY OF GREASY CUTWORM, AGROTIS SEGETUM SCHIFF. (LEPIDOPTERA: NOCTUIDAE) ON POTATO IN HIMACHAL PRADESH

Abstract

ABSTRACT: This study describes the life cycle of Agrotis segetum Schiff. under laboratory conditions. The larvae were reared on potato leaves in plastic cups and adults were offered 10 per cent honey solution. The duration of immature stages was determined. Observations were also recorded on ovipositional biology and longevity of adults. The mean duration of eggs, larvae, pre-pupae and pupae was 3.5±0.52, 24.5±0.88, 1.5±0.17, 15.4±1.07 days, respectively. The larvae passed through six instars and head capsule width recorded was 0.33±0.2 mm for first instar and 2.5±0.06 mm for the sixth instar. The dark grey larvae having light spots on the body appeared greasy, and when fully fed measured 38.1±0.87 mm long. The pre-oviposition period was 2.8±0.25 days, and the oviposition continued for 5 to 7 days. Under the conditions in which the study was conducted, the mean fecundity was 775±15.7 eggs per female. The entire life cycle from egg to adult emergence during May-June was completed in 39.0±0.3 days.