Estimation of number of generations of SpodopteralituraFab. on peanut in India during near and distant future climate change scenarios

Abstract

Studies were conducted to estimate the impact of increase in temperature on number of generations of tobacco caterpillar, Spodoptera litura on peanut for seven different locations of various agro ecological zones of the country for baseline (1961 to 1990), present (1991 to 2005), near future (2021 to 2050) and distant future (2071 to 2098) climate change (A1B) scenarios. The daily minimum and maximum temperature (MinT and MaxT) records were used to obtain cumulative degree days (DD) for each generation of insect using a temperature threshold of 10°C. Faster accumulation of degree days will making it possible for one or two additional generations with shortened life cycle (completion of generation would be 5 to 6 days earlier) of S. litura was inferred for both near and distant-future climate change scenarios (CCS) compared to baseline and present periods, at all locations. The additional number of generations and variation in the generation time of S. litura across seven growing locations of India imply the definitive and differential impacts, respectively of the projected increasing temperature in the future CCS