Population Dynamics of Cotton Whitefly Under Different Climatic Conditions

Abstract

Cotton whitefly, Bemisia tabaci (Genn.), is a sucking insect pest among the most destructive of cotton in Pakistan. During the 2024 cotton-growing season, the effects of various climatic conditions on the population dynamics of cotton whitefly in the Department of Entomology using the Bt cotton variety FH-142 were investigated. The experiment was laid out in a Randomized Complete Block Design (RCBD) and replicated three times. Whitefly populations were observed weekly throughout June-October, and meteorological data (maximum temperature, minimum temperature, relative humidity, rainfall, wind speed, and sunshine duration) were collected from a nearby weather station. Analysis of variance (ANOVA), Pearson's correlation, multiple linear regression, and principal component analysis (PCA) were used to analyze the data. The whitefly population was significantly different across the season (F = 46.82, P < 0.001), with the highest value of 18.6 ± 0.57 adults leaf⁻¹ recorded during the 37th SMW and decreasing to 2.4 ± 0.21 adults leaf⁻¹ in October. Maximum temperature and sunshine duration were significantly positively correlated with whitefly, whereas rainfall and relative humidity were significantly negatively correlated. The R² of climatic variables with whitefly abundance was 78%, and the first two PCA components explained 81.3% of the total variance. These results indicate that temperature plays an important role in whitefly outbreaks and suggest the need to incorporate weather information into the IPM program for sustainable cotton production.