Effect of Trap Size on Efficiency of Yellow Sticky Traps for Sampling Western Corn Rootworm (Coleoptera: Chrysomelidae) Adults in Corn
Field studies were conducted in Virginia cornfields in 1990 and 1991 to evaluate the effect of trap size on numbers of Diabrotica virgifera virgifera LeConte adults caught on unbaited Pherocon AM and Olson yellow sticky traps. No significant differences in trapping efficiency (i.e., catch per unit area) were detected on Pherocon AM traps whose sizes had been reduced by either 50% or 75% when compared with standard Pherocon AM no-bait traps. Likewise, no significant difference in trapping efficiency was detected between Olson traps whose sizes had been reduced 50% and full-size Olson traps (212.9 cm2). However, significantly more western corn rootworm adults per unit area were caught on Olson yellow sticky traps compared to Pherocon AM traps whose sizes had been reduced 50%. Comparative costs and precision values for reduced-size Pherocon AM and Olson yellow sticky traps are discussed.