Field Biology of Cabbage buttterfly Pieris brassicae nepalensis (Doubleday) in chitwan, Nepal

Abstract

The study about the Field biology of insect, Pieris brassicae Nepalensis (Doubleday) was conducted in Fields of Agriculture and Forestry University, Chitwan, Nepal. Activity of Pieris brassicae nepalensis was observed from nursery to harvesting stage of the crop in non-treated plots. Eggs hatched in 4-7 days with an average of 5.43 days. The insect had five instars and the mean duration of first, second, third, fourth and fifth in stars were 3.43, 6.47, 13.0, 19.7 and 29.3 days respectively. The average length of first, second, third, fourth and fifth instar-larvae were 1.7 mm, 5.71 mm, 11.29 mm, 25.29 mm and 36.29 mm respectively. The mean pupal period and total life cycle duration from egg to adult emergence was 11.71 days and 80-110 days respectively. Average adult Body Length and Wing span was measured 23.43 mm and 62.57 mm Respectively.