Seasonal incidence of Brevicoryne Brassicae L. and Pieris Brassicae L. on cauliflower seed crop in Jammu sub tropics

Investigations on the fluctuation of cabbage butterfly (Pieris brassicae) and cabbage aphid (Brevicoryne brassicae) on cauliflower (Brassica oleracea var. botrytis) seed crop variety Sel.4 in relation to abiotic factors revealed that aphid incidence started from the first week of November, 2004 attaining peak (10.30 aphid/plant) during first week of December, 2004. The aphid population exhibited non significant negative correlation with temperature (maximum and minimum), relative humidity (evening) and rainfall. The incidence of cabbage butterfly was also observed from first week of November, 2004, however the peak population (12.03 larvae/plant) was observed in the 4^th week of January, 2005. The incidence of cabbage butterfly was correlated significantly and positively with relative humidity and rainfall and negatively with temperature (minimum and maximum). Evidently increase of temperature had a limiting impact on the build up of cabbage butterfly population.