Pieris brassicae Linnaeus

Pieris brassicae or the cabbage butterfly is widely distributed in the Himalayan region and colder parts of the country damaging cabbage and other crucifers like cauliflower, radish and turnip. The female butterfly lays its eggs in clusters of 50-80 on leaf surface. The caterpillars are gregarious in the early stages and disperse as they grow in size. They skeletonize the leaves and bore into heads of cabbage as well as cauliflower. The larvae when fully fed generally pupate near the plant on any concealed place but not on the plant. In summer, the egg, larval and pupal stages are passed in 3.2, 15.6 and 7.3 days respectively, in winter the time taken is 5.5, 2.6 and 4 times more to complete the above mentioned stages, respectively.

Pieris brassicae is produced on cabbage. The adults, if wild, have to be tamed for rearing under confined conditions. From second generation onwards there would not be much problem. Two hundred adults are released per field cage (2x2x3 m) and fed on 10% sucrose solution and drinking water.

For egg laying a batch of 10 potted cabbage plants are offered daily and removed back to be placed in separate cages (60x45x45 cm) where the eggs hatch in about 3-4 days, the larvae complete development in about 16 days and the adult from the pupae emerge in 8 days. The pupae are collected from the cages and placed in the field cages a day before the emergence of butterflies or the butterflies are allowed to emerge in the cages. The butterflies are collected from rearing cages and placed in the field cages for obtaining eggs.