Population dynamics of Aphis gossypii Glov. on cotton: influence of temperature, initial density and predators

Population dynamics of the cotton aphid (Aphis gossypii Glov.) in the field is affected by complex interactions between external and intrinsic factors that can be difficult to separate. Effect's of initial aphid density, temperature and a predator on the population dynamics of A. gossypii under controlled laboratory conditions were studied. The three factors had major and interacting effects on most population parameters measured. Temperature and the initial density of aphids were key drivers of population dynamics with predation playing a role, except at the lowest temperature of 18 degrees C. The most suitable condition for the total aphid population size was the temperature of 24 degrees C. The population size declined at higher temperatures (27-30 degrees C). Obtained results suggest that if aphids experience temperatures around 24 degrees C for several weeks during the cotton-growing season, an outbreak is possible. Monitoring of aphids early in the cotton-growing season, maintaining natural predators and accurate weather forecasts are important tools for management of A. gossypii