Refuge by day, forage by night: Diel activity of vine weevil as characterised by smart monitoring

Abstract Vine weevil ( Otiorhynchus sulcatus ) is a major pest of soft fruit and ornamental crops whose nocturnal habits make monitoring challenging and understanding their diel activity is critical for improving detection and informing the timing of control measures. A smart monitoring tool equipped with imaging and environmental sensors was used to monitor adult vine weevil behaviour under semi‐field conditions, capturing 794 detections across 720 ten‐min intervals over 5 monitoring days. Weevil detections were higher during photophase than scotophase (mean ± SE: 9.48 ± 0.76 vs. 1.10 ± 0.50 weevils h −1 ), indicating refuge‐seeking behaviour in response to increasing light intensity. Generalised linear mixed models identified a strong effect of light condition on weevil activity, with detections 9.5 times more likely during daylight (rate ratio = 9.47, 95% confidence interval [CI]: 4.84–18.52) and presence odds 81 times greater (odds ratio = 81.0, CI: 10.2–645.2; p < 0.001) These results provide direct behavioural evidence of diel activity rhythms in vine weevil, supporting its classification as a nocturnal forager that aggregates in refuges during the day. Smart monitoring systems offer a scalable method for characterising pest behaviour in horticultural environments and can support more effective, behaviourally informed integrated pest management interventions.