Durability of the Pherocon AM Trap for Adult Western and Northern Corn Rootworm (Coleoptera: Chrysomelidae) Sampling

Abstract

The durability of the Pherocon AM sticky trap as a sampling tool for western corn rootworms (WCR), Diabrotica virgifera virgifera LeConte, and northern corn rootworms (NCR), Diabrotica barberi Smith & Lawrence, was examined in 1st-yr and continuous cornfields with both bright yellow and light blue traps. The relationship between temperature and trap performance was also examined. Light blue traps caught so few beetles and showed such high variability that they were deemed of little value in WCR and NCR sampling. In 1981, bright yellow traps that had been in place for 6–21 d were found to perform equally well, but not as well as newly installed traps. In 1982, traps up to 10 d old performed as well as new traps in continuous cornfields with large WCR and NCR populations. In 1st-yr cornfields with small populations of WCR and NCR, traps ≤6 d old performed as well as new traps. Trapping ability of the Pherocon AM trap apparently changes only slightly between the 3rd and 10th d following placement in the field. It is thus a flexible sampling tool that can be installed for a convenient period. Temperature was found to influence catch significantly but could not be used to improve precision because it did not account for a sufficiently large proportion of the variation in catch.