Climate driven geographical distribution and ecological niche model analysis of Schistocerca gregaria

Abstract

The erratic rainfall patterns and increased temperatures have caused an extension in the outbreaks of desert locust infestation in Africa, Middle East and Asia. This proliferation of plagues is due to warmer temperatures and more frequent rainfall. Ecological niche models were used for predicting the potential distribution of desert locust species in the study area. The purpose of the study is to predict the current and future potential distribution of Schistocerca gregaria using the ecological niche models. The geographical region selected for this study is Africa, Middle East, and Asia. The model is calibrated in Africa, Middle East, and Asia. For this purpose, the application used is Maxent through kuenm R package based on the environmental variables of temperature and rainfall. The results are interpreted in term of suitable area in Asia, Middle East, and Africa. Results showed the increased potential distribution of desert locust species in the region under study with increased suitability percent distribution of Schistocerca gregaria. The jackknife tests showed the important predictive environmental variables for the desert locust to be Bio 16 (precipitation of the wettest quarter) and the Bio 4 (the temperature seasonality) for the current and future distribution, respectively. The partial ROC values showed that the model performed well for the current and future distribution of Schistocerca gregaria. According to the future results of 2050 the highly suitable areas will increase. The highly suitable area for future distribution accounts for 32.6% and 33.7% for RCP 4.5 and RCP 8.5 respectively; this situation is alarming because the region is already food famine and dependent upon agriculture for its economy and the specie searches for food after breeding and feeds upon agricultural area. These results will help in understanding the distribution that will assist the policy makers and to deal with future outbreaks and plagues in Asia, Africa, and the Middle East.