Temperature based phenology model for predicting establishment and survival of Spodoptera litura (Fab.) on groundnut during climate change scenario in India

Abstract

Studies were conducted to develop temperature-based phenology model for Spodoptera litura on groundnut, at both constant and fluctuating temperatures and to predict the possibility of pest risk in future climate change scenarios of India using ‘stochastic simulation tool’ in Insect Life Cycle Modelling (ILCYM) software ,which is based on rate summation and cohort up-dating approach. Phenology model predicted temperatures between 25oC and 30oC as the favourable range for S. litura development, survival and reproduction. The intrinsic rate of increase (rm), and finite rate of increase (») increased with increase in temperature from 15oC to 30oC and decreased with increase in temperature. Intrinsic rate of increase (rm), varied from 0.05 females/female/day at 15oC to 0.17 females/female/day at 30oC. S. litura population attained a maximum net reproductive rate ‘Ro’ (334.09 females/female/generation) and total fecundity (1041.88 individuals/ female/generation) at 27°C temperature. Simulated life table parameters were used to determine indices such as the establishment risk index (ERI), the generation index (GI), and activity index (AI) by using the ‘Population distribution and risk mapping’ module of software during present and future climatic scenarios and significant increase in AI and ERI with higher GI at future (2050) climatic conditions compared to current (2000) climatic conditions indicating the strong suitability for establishment and survival of S.litura in India.