Correlation of weather parameters with diamondback moth (Plutella xylostella) and semilooper (Trichoplusia ni) on cabbage

The peak activity of diamondback moth (2.60 larvae/plants) and semilooper (0.5 larvae/plant) on cabbage was observed during first week of March (10^th MW) when the prevailing weather parameters viz. maximum temperature, minimum temperature, morning relative humidity, evening relative humidity, bright sunshine hours and rainfall were 27.8°c, 16.3°c, 91 per cent, 53 per cent, 6.6 h and 70.7 mm, respectively. negatively significant correlation with bright sunshine hours (r =-0.269) was observed between diamondback moth larval population. The correlation of semilooper population with morning relative humidity (r =-0.217) and bright sunshine (r =-0.159) showed significantly negative influence. The coefficient of determination (R²) indicated that the weather parameters contributed for 73.33 and 94.28 per cent of total variation in the population of diamondback moth and semilooper on cabbage, respectively.