author(s)
Bashir Ahmad, Ahmad-Ur-Rahman Saljoqi, Muhammad Saeed, Farman Ullah and Imtiaz Ali Khan

abstract
Studies were carried out from June to November, during 2012 and 2013 at Peshawar, Pakistan to determine the population dynamics of Plutella xylostella (Lepidoptera: Plutellidae) in Cauliflower, Brassica oleracea L. var. botrytis and its correlation with weather parameters. The highest mean population of larvae and pupae (4.75±2.14 and 6.7±1.71) per plant was recorded in September whereas the lowest (0.2±0.41 and 0.4±0.71) was recorded in July, 2012 and 2013 respectively. A negatively nonsignificant correlation (r = -0.31 and -0.18) was recorded with maximum temperatures, whereas with minimum temperature, the association (r = 0.02 and 0.06) was positively non-significant. Percent Relative Humidity showed a positively significant (p<0.05) relationship (r =0.79 and 0.67) with population dynamics whereas a negative correlation ((r = -0.98 and -0.46) was recorded with total rainfall but was statistically significant in 2012 and non-significant in 2013. Multiple regression models showed 90-98% (R2) interaction between the population of P. xylostella and weather parameters.