Seasonal Incidence of Major Insect Pests and their Natural Enemies in Brinjal

Abstract

Seasonal incidence of major insect pests and coccinellid predators in brinjal was examined at Karekere, Hassan district, during the Kharif, Rabi, and Summer seasons of 2023–24. The brinjal variety ‘Arka Harshitha’ was cultivated in untreated plots, and observations were recorded weekly on five randomly selected plants at three locations. Aphids, leafhoppers, hadda beetles, and the brinjal shoot and fruit borer were the principal pests recorded, while coccinellids represented the observed natural enemies. Pest and predator abundance varied across seasons and standard meteorological weeks. During Kharif, maximum temperature was positively associated with coccinellids, epilachna beetles, and brinjal shoot and fruit infestation, whereas rainfall was negatively associated with leafhopper abundance. During Rabi, maximum temperature was positively associated with leafhoppers, coccinellids, epilachna beetles, and shoot and fruit infestation. Minimum temperature and relative humidity were negatively associated with shoot infestation, and minimum temperature was negatively associated with fruit infestation. During Summer, relative humidity was positively associated with aphids, leafhoppers, and coccinellids, while maximum and minimum temperatures were positively associated with epilachna beetles. Fruit infestation was negatively associated with both maximum and minimum temperatures. The findings demonstrate clear seasonal variation in pest and predator activity and indicate that weather variables may assist in identifying periods of increased pest occurrence under conditions comparable with the study location.