Sporadic Incidence of the Green Chafer Beetle (Chiloloba acuta) on Maize in the Tarai Region of Uttarakhand, India

Abstract

Aims: The green chafer beetle is considered an occasional pest across different crop ecosystems in the Tarai region of Uttarakhand, India. The present study aimed to examine its population dynamics under natural field conditions on maize crop. Study Design: Maize variety PCM-4 was sown manually at a spacing of 60 × 30 cm in six replications following Randomised Block Design, each comprising a plot of 5 × 6 m. Ten maize plants were randomly selected for sampling. Beetle counts were recorded from the germination stage through to crop maturity. Place and Duration of Study: The investigation was carried out during the kharif season of 2024 at the Norman E. Borlaug Crop Research Centre, G.B. Pant University of Agriculture and Technology, Pantnagar. Methodology: Data of adult beetle population along with key abiotic factors such as maximum and minimum temperature, morning and evening relative humidity, sunshine duration, and rainfall were recorded and analysed using simple correlation and regression techniques. Results: Chafer beetle infestation on maize in Pantnagar occurred mainly between the 38th and 45th standard weeks during the kharif season of 2024. Pearson’s correlation analysis revealed significant negative correlations between beetle population and minimum temperature (r= –0.613*), morning relative humidity (r= –0.665**), and evening relative humidity (r= –0.747**). Sunshine hours exhibited a significant positive correlation with beetle abundance (r= 0.588*), indicating that brighter and longer sunshine periods favoured chafer beetle activity. Conclusion: The study concludes that chafer beetle infestation in maize at Pantnagar is sporadic, emerging during the tasseling and pollen-shedding period. Low minimum temperature, both maximum and minimum relative humidity, reduce beetle buildup, whereas sunshine hours play a major role in enhancing adult beetle abundance.