Estimating the Optimal Control Areas of Two Classical Biocontrol Agents Against the Fall Armyworm Based on Hotspot Matching Analysis

Spodoptera frugiperda, the fall armyworm (FAW), is a widespread and polyphagous crop pest, causing serious crop yield losses worldwide, especially maize and other cereals. Biological control (biocontrol) is considered as the generally safer and more environmentally benign strategies compared to chemical insecticides in managing FAW. Chelonus insularis and Eiphosoma laphygmae are two promising classical biocontrol parasitoids against FAW. However, the optimal control areas for FAW with the two parasitoids in its invasive ranges remain unclear. This study is first time to integrate species distribution models and hotspot analysis to estimate the optimal areas for controlling FAW with these two parasitoids worldwide. Key variables influencing distribution include human influence index, temperature, and precipitation. The optimal control areas of FAW with C. insularis and E. laphygmae are in most of sub-Saharan Africa, Mediterranean regions, eastern, southern, and southeastern Asia, and Oceania. These areas are expected to expand to high-latitude areas under changing climatic conditions. Niche comparisons indicated that the FAW and C. insularis niches were closely aligned. Chelonus insularis and E. laphygmae are potentially effective against FAW in Africa, Asia, and Oceania. Our findings offer insights into the strategic use of the two parasitoids against FAW worldwide.