Trends in Helicoverpa Egg, Larval and Adult Population Changes in the Chickpea Environment of Orissa
The population dynamics phenomena of the gram caterpillar, Helicoverpa armigera (Hubbner) on chickpea were investigated during winter 1989–90 through 1991–92 under the North central plateau agro-climatic zone of Orissa. The average data across years indicated peak oviposition during 52nd standard week coinciding with the late vegetative to flower initiating stage of the crop. Peak egg density was observed within the thermal ranges of 24.6°C (mean max.) to 11.5°C (mean min.) and at a RH of 72.2%.