Evaluation of Baiting Techniques for Sampling Wireworms (Coleoptera: Elateridae) Infesting Wheat in Washington1

Abstract

Field comparisons of several baits in attracting wireworms, primarily Great Basin wireworms, Ctenicera pruinina (Horn), showed that fewer wireworms were found at stations baited with carrot, potato, or wheat bran than at those baited with a 1:1 whole wheat-corn mixture or wheat flour. Counts at stations baited with whole ground wheat, whole wheat, and whole corn were intermediate. Baits consisting of a 1:1 wheat-corn mixture, either dry or presoaked in water, either covered with a polyethylene sheet or not, and exposed for 1, 2, or 3 weeks during March through June in fallow ground, were evaluated for their efficiency in attracting wireworms. In general, presoaking or covering baits made little difference in the mean number of wireworms attracted as compared with dry or uncovered baits. However, the bait combination attracting the highest number of wireworms was soaked, covered, and exposed for 3 weeks in April. Low soil temperature was apparently the limiting factor in attracting wireworrns to baits in March, whereas low soil moisture was the limiting factor in June. When the mean number of wireworrns from all unbaited soil samples was compared with that at baits, different ratios were obtained for each of three exposure periods each month. However, if additional studies in other areas can verify the efficacy of the baiting technique, it could be used to estimate wireworm population densities in the field.