The population dynamics of Heliothis armigera [Helicoverpa armigeral was studied on chickpea (Cicer arietinum) sown on various dates in Bihar, India, in 1984-85. On crops sown on 12 or 22 October, the larval population was fairly low during December; during this month the minimum daily temperature was a mean of 7.5% and the rate of parasitism by the ichneumonid Campoletis chlorideae was high (50-53.3%). The population of H. armigera was highest in the first week of March, when the chickpea crop was sown on 22 October, 1 or 21 November or I December. However, peaks of the pest also occurred on 25 January and I I February on the crops sown on 12 October and I I November, resp. These peaks occurred when the minimum daily temperature was between 10.4 and 14.4'C, rainfall was 17, 30 and 12 mm during December, January and February, resp., and the rate of parasitism was below 20%. none