Population Fluctuation of Various Insect Pests of Summer Sorghum in North Gujarat, India

The present study was conducted during the summer of 2024 at the Agronomy Instructional Farm, Sardarkrushinagar Dantiwada Agricultural University (SDAU), Sardarkrushinagar, Gujarat, to investigate the population dynamics of major insect pests and natural enemies of sorghum, and their relationships with abiotic factors. Observations on pest incidence were recorded weekly from crop emergence to harvest using six quadrats, with five plants examined in each quadrat. The results revealed that shoot fly (Atherigona soccata) damage reached a maximum of 40% dead hearts during the 15^th standard meteorological week (SMW), while stem borer (Chilo partellus) infestation peaked at 40.00% during the 19^th SMW. The shoot fly complex, including Ectecephala spp. and Oscinella spp., showed peak activity during the 17^th SMW. Among foliage feeders, ash weevil population reached a maximum of 0.73 weevils' plant^-1 during the 18^th SMW, while leafhopper population peaked at 0.56 hoppers plant^-1 during the 21^st SMW. The natural enemy, like spiders, attained a maximum population of 0.23 spiders' plant^-1 during the 18^th SMW. Correlation analysis indicated a significant negative relationship between wind speed and shoot fly incidence, whereas bright sunshine hours showed a significant positive correlation with stem borer and leafhopper populations. Maximum relative humidity was positively associated with spider abundance.