Impact of eCO2 and Temperature on Aphis craccivorakoch. onGroundnut and Future Pest Status During Climate Change Scenarios

Abstract

Studies were conducted to quantify the direct effects of temperature and indirect effect of elevated CO2 (eCO2 ), on Aphis craccivora Koch. on groundnut (Arachis hypogaea L.). The mean development time (DT) of nymph was significantly reduced by 1-2 days from 20 to 35° C temperature at eCO2 over ambient CO2 (aCO2 ) conditions. Increased production of offspring was noticed at eCO2 . The thermal requirement of nymph varied from 74-102 DD on eCO2 with temperature in the range of 20-30° C as against 90-130 DD on aCO2. Non-linear mostly quadriatic relationship of lifetable parameters rm, Ro , T and λ varied with temperature and CO2 and found to have nonlinear relationship. Prediction of pest scenarios based on PRECIS A1B emission scenario data at eleven groundnut cultivating locations of India during near (NF) and distant future (DF) periods showed that increase of ‘rm’ and ‘λ’ with varied ‘Ro ’ and reduced ‘T’. Similar trends were reflected in three decadal periods of NF also. The present results indicate that incidence of A. craccivora is likely to be higher in the future climate change periods.