Pheromone-baited cone traps are efficient for catching the bean webworm, Pleuroptya ruralis (Lepidoptera: Crambidae)

Abstract

The bean webworm, Pleuroptya ruralis (Scopoli) (Lepidoptera: Crambidae), is a serious soybean pest in northern Japan. Monitoring P. ruralis has been carried out by beating the soybean canopy and counting the number of displaced adults; however, this method is laborious and time-consuming. To develop attractant lures for monitoring traps, the sex pheromone of P. ruralis has already been identified; however, pheromone-baited traps have failed to catch a sufficient number of moths. Previous trials solely utilized delta traps; cone traps, which are demonstrated to be effective for trapping some crambid species, have not yet been evaluated in P. ruralis. In this study, we compared the capture efficiency of pheromone-baited cone traps with those of pheromone-baited delta traps along with the beating method. The number of P. ruralis caught by the cone traps was significantly and 25 times larger than those caught by the delta traps. This result indicates that the trap design dramatically affects the capture efficiency of P. ruralis, and the cone trap is efficient for capturing P. ruralis. Moreover, the cone traps detected P. ruralis earlier than the beating method. The present data results suggest that pheromone-baited cone traps are useful for monitoring P. ruralis.