Regional Research and Technology Transfer Station, Orissa Aricultural University and Technology, Keonjhar-758002, Orissa, India.
The spatial distribution of Helicoverpa armigera (Hubner) larvae in chickpea investigated during the crop seasons of 1989–90, 1990–91 and 1991–92 through Variance: mean ratio revealed that the pattern was clumped despite fluctuations in the mean larval density across locations and crop seasons. In most cases (57.6%) the contagious nature of Helicoverpa larvae was evident from the Chi-square index values. The variation in the magnitude of aggregation across years suggested separate sampling plans for different years for precise estimation of the larval population density in chickpea.
