Future warming enhances rates of population increase of arthropod crop pests globally

Arthropod herbivores cause severe crop yield losses worldwide. Global warming is expected to shift their ranges, phenologies and performances, highlighting the need for improved forecasts of their potential expansion and impacts on food security. After decades of experimental research on thermal biology of arthropod crop pests, available data and tools now allow to model their temperature‐dependent population growth (i.e. population‐level thermal performance curves, or TPCs), which approximate their fundamental thermal niches. Thermal limits of these TPCs can inform biogeographic predictions on latitudinal adaptation to cold and heat, while TPC predictions for population growth rates help assess whether warming will benefit or constrain pest populations. We compiled a dataset on the thermal biology of arthropod crop pests and fitted TPCs to examine the projected shifts in performance under historic and future climates relative to their thermal niches, which were examined through modelling the latitudinal variation of their population‐level thermal limits. Our findings highlight that most arthropod crop pests are projected to increase their thermal potential for population growth under warming by 2050, with temperate populations retaining room to grow but tropical populations increasingly exposed to heat stress. These findings can be explained by the asymmetric variation of thermal niche limits for these intrinsic rates of population increase, since we found that lower thermal limits declined with latitude, while upper thermal limits remained constant.