Prediction of High-Risk Probability Areas under Current and Future Climate Scenarios in India for the Establishment of Fall Armyworm

Abstract

The Fall Armyworm (FAW) or Spodoptera frugiperda, is an endemic and agriculturally important insect pest in tropical and subtropical regions of the Americas causing severe impact estimated at millions of dollars. FAW has been recently identified for the first time in India and is also a first record in Asia threatening the food security and livelihoods of millions of farmers. The insects are affected by climatic factors, and climate change may affect geographical distribution, abundance, growth rate, survival, mortality, number of generations per year and other characteristics. These climate change effects on insects are difficult to project due to complex interaction among insects, hosts and predators. Moreover, agricultural pest management may become more challenging under future climate change and variation. The present study aims to project the impact of climate change on future suitability for the expansion of FAW as well as highlight the high risk probability areas due to the pest using the historical and future climatic conditions. The modelling was carried out using CLIMEX model, GIS, the known distribution of the species and the CliMond meterological database. The analysis has indicated high climatic suitability for FAW occurrence in India with Eco-climatic Index (EI) values above 20. Further, the high risk probability areas for the FAW establishment up to district level were also identified for the major maize growing states. The areas where the pest is currently reported in the country are coinciding with the predicted potential areas in India validating the current analysis. The analysis using two general circulation models (GCMs), CSIRO MK3.0 and MIROC-H, for 2030 and 2050 under the A2 Special Report on Emissions Scenarios (SRES) indicated the possible reduction of climatically suitable areas for the FAW establishment in India. This kind of analysis assessing the possible impacts of FAW under future climate conditions is essential for the future economic production of crops.