Behavioural Studies on Aphis craccivora Koch. Following Exposure to Aphid Alarm Pheromone
Aphis craccivora Koch, responded mainly by falling or walking from its feeding site on groundnut plant when it was exposed to alarm pheromone. This phenomenon was increased or decreased to a certain limit with the increase in period or distance of exposure. The dispersion of aphid through falling decreased and walking increased, with the increase in distance of alarm pheromone source. The adult aphids responded more than its immature stages to alarm pheromone. The higher amount of alarm pheromone caused aphid response mainly by falling. The aphids were dislodged by alarm pheromone within distance of 20 cm. The recolonization of aphids dispersed by alarm pheromone to their original sites was 78.61 per cent after 24 hours of exposure.