Comparative efficacy of five types of trap for woodborers in the Cerambycidae, Buprestidae and Siricidae

1 Traps of four new designs were tested against the conventionally used multiple-funnel trap to determine whether trapping of large wood-boring insects can be improved in western Canada. All four new traps used a large collecting receptacle containing detergent-laced water, and three presented a prominent visual silhouette above the receptacle. 2 In total, 27 336 large woodborers were captured from 10 June to 30 September in an experiment in the southern interior of British Columbia, and 4737 from 6 June to 27 July in an experiment in northern Alberta. The woodborers captured in the British Columbia experiment were mainly beetles in the families Cerambycidae (79%) and Buprestidae (15%), and woodwasps in the family Siricidae (6%). Most woodborers, e. g. three Monochamus spp. and Xylotrechus longitarsus (the predominant cerambycids), were captured throughout the summer, with peak captures in August. 3 Cross-vane, pipe and stacked-bottomless-flower-pot traps were generally superior to pan and multiple-funnel traps for insects in nine taxa, but cross-vane traps were the most effective overall, trapping 32% of all insects captured. 4 The large number of target insects captured in a relatively small number of traps in the two experiments suggests that employment of an efficacious trap with a large vertical silhouette and a wide, escape-proof collecting receptacle could make mass trapping of large woodborers in timber processing areas operationally feasible. 5 Because the most effective traps were unstable in the wind, and the detergent-laced water captured unacceptably high numbers of small mammals, design modifications are necessary. We are currently developing a wind-firm trap, with a prominent vertical silhouette, a wide collecting surface, and an escape-proof, but dry collecting receptacle.