Authors:M. Tóth, I. Sivcev, I. Ujváry, I. Tomasek, Z. Imrei, P. Horváth and I. Szarukán
Trap designs baited with the synthetic sex pheromone have been optimized for trapping of the western corn rootworm Diabrotica v. virgifera LeConte (Coleoptera: Chrysomelidae) (WCR), which has recently been introduced into Europe. The best trap design proved to be the sticky “cloak” trap (code name “PAL”), which catches only males, and is being used in many countries of Europe for detection and monitoring the spread of the new pest. Preliminarily the range of attraction (as defined by Wall and Perry, 1987) of the pheromone traps was estimated to be <10 m. The performance of yellow sticky plates (used by others for monitoring of the pest) was insignificant as compared to the activity of the pheromone baited traps, and yellow colour had no discernible effect on catches in pheromone traps. The known floral lure of WCR containing 4-methoxy-cinnamaldehyde and indole proved to be active also towards the population in Europe, attracting both females and males. Yellow colour slightly increased catches by the floral lure, hence a yellow sticky “cloak” trap has been developed (code name PALs). Pheromone baited PAL traps caught a total of about 4 times more beetles than the floral baited PALs, which latter however appeared to be preferentially active for females. When placed into the same trap, the pheromonal and floral lures did not interfere with each other's activity.