Climate change and geographical distribution projections for major leaf beetles (Coleoptera: Chrysomelidae) in Saudi Arabia

Climate change has a substantial impact on the quality and diversity of insect pests, which may have adverse ecological and economic effects. The family Chrysomelidae represents one of the most economically and ecologically important groups within Coleoptera, with species acting as agricultural pests and contributing substantially to biodiversity in arid regions. Based on bioclimatic, topographic, and vegetation data, the current and future distributions of 4 chrysomelids (Caryedon acaciae (Gyllenhal, 1833), Chaetocnema pulla Chapuis, 1879, Phyllotreta cheiranthi Weise, 1903, and Spermophagus sericeus (Geoffroy, 1785)) in Saudi Arabia were predicted using MaxEnt modeling for 2050 under 2 Shared Socioeconomic Pathways (SSPs), SSP126 (low emission) and SSP585 (high emission) scenarios. The leaf beetle models showed strong performance, with average area under the curve (AUC) values ranging from 0.86 to 0.96 and average TSS values ranging from 0.52 to 0.65. Five predictors were chosen for each species from 21 environmental variables. The results show that the key ecological factors that influence species distributions varied, with vegetation being the most influential. According to habitat suitability maps, in the future, such distribution will be severely altered, mostly by climate change. More precisely, C. acaciae will face minor range shifts, while C. pulla, P. cheiranthi, and S. sericeus will expand their ranges substantially, especially in the Eastern Province. Our results confirm the importance of implementing adaptive pest-management strategies to address the potential range expansions of various agricultural pests, which could intensify local ecological challenges and pose a heightened threat to agricultural systems.