Biology and Lifetable of Diamond Back Moth <i>Plutella xylostella</i> (L) on Cruciferous Crops

Plutella xylostella L., commonly known as diamondback moth (DBM), is an important pest of cruciferous crops worldwide. In this study, biology and life table parameters of P. xylostella, reared on cauliflower (Brassica oleracea L. var botrytis), cabbage (B. oleracea L. var capitata) and radish (Raphanus sativus L.), were measured to evaluate the suitability of these plants. The developmental period, survivorship and fecundity of P. xylostella were statistically same on all three test plants, however longevity of female was significantly higher on cabbage compared to cauliflower and radish. The mortality of larvae was significantly higher during early developmental stages, i.e. first and second larval instars, when reared on cauliflower and cabbage leaves but it was evenly distributed throughout the developmental stages when reared on radish. Moreover, the intrinsic rate of increase (rm) was highest on cauliflower (0.35) as compared with cabbage (0.29) and radish (0.33), rendering it the most suitable host plant for P. xylostella. Present study may be helpful in calculating population dynamics and predicting time of action threshold for the application of insecticides and other control measures for the management of this pest.