Pest–weather dynamics in tomato: a study from North-Western Punjab

Abstract

Seasonal incidence of insect pests of tomato was monitored weekly and analysed in relation to key meteorological parameters such as maximum and minimum temperatures, relative humidity, and rainfall. Sucking pests such as Aphis gossypii and Bemisia tabaci, along with lepidopteran pests viz., the leaf miner Tuta absoluta and the fruit borer Helicoverpa armigera were first observed during the 41st and 43rd Standard Meteorological Weeks (SMW), respectively. The peak populations of pest were recorded during the 48th SMW, with peak densities of A. gossypii (17.78 nymphs/plant), B. tabaci (21.8 nymphs/plant), T. absoluta (5.2 larvae/plant), and H. armigera (4.2 larvae/plant). Correlation analysis showed that maximum temperature had a strong positive association with pest incidence, with correlation coefficient values of 0.719, 0.658, 0.622, and 0.689 for A. gossypii, B. tabaci, T. absoluta, and H. armigera, respectively. Minimum temperature exhibited weak, non-significant negative correlations (–0.290 to –0.216). Relative humidity showed negative non-significant correlation for A. gossypii (–0.523), B. tabaci (–0.565), and H. armigera (–0.411), while T. absoluta showed a significant negative correlation (–0.580). Rainfall showed significant negative correlations with all four pests. Understanding the seasonal occurrence of insect pests in tomatoes identified the dynamic nature of pest challenges throughout the crop. This awareness may be useful in establishing early and effective control measures and reducing the environmental impact associated with pest management techniques.