Forecasting of Helicoverpa armigera populations and impact of climate change

Abstract

Helicoverpa armigera (Hubner) is a polyphagous insect pest and has been reported to feed on at least 181 plant species belonging to 45 botanical families in India. This insect pest has become of national importance because of huge losses caused to the high value crops such as cotton, soybean, tobacco, pulses, vegetables and cereals etc. Forecasting of the pest occurrence and peak activity periods is the prerequisite for an economically viable, environmentally sound and easily adaptable pest management programme. Adult population of H. armigera has been monitored successfully throughout India with the help of pheromone traps. By using the pheromone trap data, egg and larval count in the fields, damage caused to the crops and meteorological data, especially rainfall and temperature, region-specific prediction models have been developed and validated for Andhra Pradesh, Karnataka, Uttar Pradesh and Punjab. Rainfall has been found to be important factor in forecasting H. armigera in Andhra Pradesh and Karnataka. Temperature played the major role in the prediction model developed and validated for Uttar Pradesh. Whereas in Punjab, the peak population of H. armigera during March-April is dependent on temperature and humidity in February, while the high population during October depended on the rainfall during the rainy season.