A review on true dung beetles' evolutionary and ecological responses to temperature and impacts on ecosystem functions

Changing climates present organisms with novel selective pressures, with consequences for both biodiversity and ecosystem functioning. Organisms may respond to all of these challenges through range shifts, rapid evolution, phenotypic plasticity or a combination of strategies. The true dung beetles (Scarabaeidae: Scarabaeinae) have emerged as a valuable system for studying these responses and their interactions. With more than 6990 described species worldwide, they play critical roles as ecosystem engineers, particularly in agricultural systems where they contribute to dung decomposition, nutrient cycling and pest control. However, the ecological and economic benefits they provide are increasingly threatened by environmental change. In this review, we synthesize the literature on dung beetle responses to variation in temperature across ecological and evolutionary timescales. We discuss their evolutionary history, the role of temperature in shaping developmentally plastic and evolutionary responses, evidence for climatic divergence and range shifts and the implications for ecosystem functioning. Overall, there is strong evidence for thermal plasticity in life history, behaviour and morphology. There is also a growing number of studies demonstrating evolutionary divergence on relatively short timescales. Elevational and geographic range shifts have also been reported but remain poorly documented. Key knowledge gaps include (i) limited understanding of the evolvability of complete thermal performance curves, which constrains evolutionary predictions, (ii) insufficient knowledge about how plastic and evolutionary responses scale up to affect ecosystem functioning in complex agricultural environments and (iii) the largely unexplored role of symbionts in dung beetle ecology and evolution. We outline research priorities that address fundamental questions in ecology and evolution while also informing the conservation of dung beetle diversity and the ecosystem services they provide in both agricultural and natural systems.