Biology of Pieris Brassicae (Linn.) on Different Brassica Species in the Plains of Punjab

Biology of Pieris brassicae reared on Brassica napus, B. juncea, B. rapa, and B. carinata was studied. Adult butterflies, collected in November from the plains of Punjab, India, were sexed, paired, and released onto the four Brassica spp. in a greenhouse. In a multigeneration study (Parental, F1, and F2), the effect of the four Brassica spp. on the egg laying, incubation period and hatching percentage was assessed in a greenhouse study. Hatched larvae were collected, reared on fresh leaves of respective Brassica spp, in laboratory conditions. Data collected on larval stadia, pre-pupal and pupal durations, adult longevity, and sex ratio were assessed to understand the effects of these four species. Of the four species, B. carinata, with a shorter incubation period, higher hatching percentage, and shorter developmental periods was most susceptible. In this study, B. rapa was the most resistant species and may be recommended for further breeding programs in order to reduce the economic damage caused by P. brassicae.