Habitat suitability for desert locust across arid and semi-arid regions of India

This research uses a MaxEnt habitat suitability model to map morph-specific desert locust risk zones (hoppers, bands, adults, swarms) across arid and semi-arid Rajasthan, India, to guide targeted field surveillance. Desert locusts (Schistocerca gregaria, Forskål, 1775) inflict severe crop losses across arid and semiarid regions of Asia and Africa, jeopardizing food security for large groups of the population. This study identifies specific environmental risk zones for desert locusts through different morphs in Rajasthan, India. The present work incorporated the occurrence records from UN-FAO, spanning 36 years (1986-2021), combined with 12 environmental variables representing climate, soil, vegetation, and topography to predict suitable habitat for solitary and gregarious phase adults, hoppers, bands, and swarms. Results reveal marked ecological differentiation among morph-specific models, which makes the study unique. 

Findings show green vegetation (winter and monsoon), temperature (pre-monsoon, winter), wind speed, and sand content capacity are the most influential factors for locust distribution in India. Hoppers and bands remain concentrated in sandy zones of the Thar Desert, while adults and swarms occupy border and central portions (extending toward Jodhpur and Churu). 32% of the total geographical extent of Rajasthan serves as a high-risk surveillance zone. The final output of the habitat suitability zone can guide targeted surveillance to seasonal locust movements and will facilitate early detection before swarms reach the farmland.