Blending of pheromone lures for two exotic European pest elaterid beetles

Two exotic European click beetle species, Agriotes obscurus and Agriotes lineatus, were introduced into the lower Fraser valley of British Columbia over a century ago, and are now predominant pests of a number of arable crops. A semiochemical-based method of monitoring both species has been developed as a part of an integrated pest management plan, and there is interest in mass trapping with pheromones as a management tool. A. obscurus females produce primarily geranyl octanoate (G8) and geranyl hexanoate (G6), while A. lineatus females produce both G8 and geranyl butanoate (G4). The current studies examined the possibility of using a blend of G8, G6, and G4 components in a single lure to trap both species simultaneously. A blended G8, G6 and G4 lure in a 1:1:1 ratio was, on average, 1.42 times more attractive to A. lineatus males than standard A. lineatus pheromone lures, but caught only 0.24 times the number of A. obscurus in standard A. obscurus traps. Blended traps, therefore, are effective for monitoring and mass trapping of A. lineatus, but only for detection of A. obscurus.