Factors influencing vine weevil monitoring tool efficacy

Abstract: Monitoring is an integral component of integrated pest management (IPM)
programmes used to support management decisions. Vine weevil, Otiorhynchus sulcatus
(Coleoptera: Curculionidae), continues to cause economically significant losses in horticultural crops. The continued importance of this pest is in part due to an inability to detect the presence of this species within crops before losses have occurred. Behavioural responses of adult vine weevils to visual (monitoring tool colour, height and diameter as well as monitoring tool and plant density) and olfactory (host plant and conspecific) cues were investigated under glasshouse conditions to determine the importance of vine weevil monitoring tool characteristics. Monitoring tool colour, height and diameter all influenced monitoring tool efficacy, with individuals exhibiting a preference for black, tall and large-diameter monitoring tools. The total number of vine weevils recorded under glasshouse condition was also influenced by the number of monitoring tools deployed, with a higher number of vine weevils recorded when the number of monitoring tools was increased from one to two and from two to four. By contrast, when the number of plants was increased from one to four and from four to eight, the number of vine weevils recorded in monitoring tools was not significantly affected. Odours released from yew foliage affected the behaviour of vine weevils, with more weevils recorded in monitoring tools baited with yew than in unbaited monitoring tools. Whereas odours released by conspecifics did not affect the number of weevils recorded in monitoring tools. This study indicates that olfactory and visual cues affect the behavioural responses of vine weevil adults and provides information on key factors that influence vine weevil monitoring tool efficacy that may assist in designing a commercially available monitoring tool for this pest.