Pollinator, pest or neither? Long‐term dynamics and functional role of cyclocephaline beetles on macaúba palm

The ecological roles of insect visitors to crop plants can range from beneficial pollinators to detrimental pests, often varying with environmental context. Cyclocephaline beetles are frequent visitors to the economically important macaúba palm ( Acrocomia aculeata ), but their net impact remains debated as cultivation expands. This study addresses the central question of whether these beetles function as pollinators, florivores or commensals in a Neotropical savanna agroecosystem. Over 15 years (2010–2024), we combined behavioural observations, multi‐scale abundance monitoring and exclusion experiments to resolve this interaction. Beetles exhibited crepuscular activity, primarily feeding on pollen and using non‐reproductive floral chambers for shelter, with no significant quantitative evidence of effective pollination. Experimental exclusion revealed that while total visitor exclusion caused reproductive failure, excluding only cyclocephaline beetles did not significantly alter fruit set compared to open pollination. Long‐term monitoring showed a significant decline in total beetle abundance over the decade, structured primarily by seasonal flowering phenology, with no robust evidence for independent short‐term climatic effects. We conclude that the interaction at this site is predominantly commensalistic (+/0). However, given the context‐dependent nature of these interactions, we argue that sustainable management requires adaptive monitoring (Integrated Pest Management, IPM) rather than a priori pest assumptions, particularly as agricultural intensification and climate variability increase.