Seasonal Incidence of Cabbage Butterfly, Pieris brassicae Linn. on Ethiopian Mustard, Brassica carinata

摘要

Seasonal incidence of Pieris brassicae on Swarnim variety of B. carinata was studied, during rabi 2004-05. The incidence of the adult butterfly was noticed from the second standard week of 2005 while oviposition started from the standard week 5 and reached its peak during the standard week 8 of 2005. Number of eggs per patch ranged from 23 to 185. Larvae started emerging from standard week 6 onwards. Highest number of larvae (86.7 larvae/plant) was observed during the standard week 7. The larval population started declining from the standard week 12 and the lowest number of larvae (7.6) per plant was recorded during the twelfth standard week, as migration started for pupation.