Potential risk of establishment and survival of cotton aphid Aphis gossypii in India based on simulation of temperature-dependent phenology model

Abstract

The cotton aphid, Aphis gossypii, is a major sap sucking insect of cultivated cotton, Gossypium sp. We investigated the effects of temperature on the biological parameters of A. gossypii by fitting different non-linear models to the data obtained from constant temperature experiments carried out between 12 and 32 °C. The pest risk in different geographical areas was simulated using GIS tools and represented by two spatial indices viz. establishment risk index (ERI) and generation index (GI). The results revealed that the development rate as a function of temperature increased linearly until approximately 27 °C, after which it became non-linear. Mean longevity of adult female was highest at 12 °C (10.10 ± 0.33 days) and shortest at 32 °C (3.70 ± 0.14 days). The lower and upper development threshold temperatures predicted for immature development of A. gossypii were 6.24 °C and 34 °C, respectively. The temperatures between 22 and 27 °C were found as favourable range for A. gossypii development, survival and reproduction. Majority of the Indian cotton areas were predicted optimally suitable for establishment and survival of A. gossypii (ERI > 0.6 and GI > 30.0). The risk mapping based aphid management strategy is suggested in the conclusion section of this article.