Developing traps for the overwintering tree-of-heaven weevils Eucryptorrhynchus scrobiculatus and E. brandti (Coleoptera: Curculionidae)

BACKGROUND The tree-of-heaven root and trunk weevils, Eucryptorrhynchus scrobiculatus (TRW) and E. brandti (TTW) are important boring pests of Ailanthus altissima in China. Overwintering TRW and TTW adults can continue to damage A. altissima trees and reproduce after they emerge from the soil each year. There is a lack of studies regarding the development of control measures during the overwintering period. A polyethylene terephthalate bottle trap (PETBT) and corrugated paper box trap (CPBT) were evaluated for their ability to trap TRW and TTW adults descending from trees to overwinter in the soil in Wutongshu and Shabatou locations in Ningxia, China. RESULTS Significantly more overwintering TRW adults were caught by the PETBT than the CPBT. There were no significant differences in the TTW captures in PETBT when compared to the CPBT. Both PETBT and CPBT have little effect on trapping overwintering TTW adults. Further trapping studies showed that PETBT treatments significantly reduced overwintering TRW numbers caught in population monitoring trap nets placed on the A. altissima tree trunks (an average annual reduction of 42% than the untreated trees). CONCLUSION These results demonstrate that PETBT is effective for trapping overwintering TRW adults. PETBT could be recommended as an alternative for managing TRW in the framework of integrated pest management.

Automated summary

The study found that the PETBT was effective in trapping overwintering TRW adults, resulting in a significant reduction in their numbers compared to untreated trees. The PETBT could be recommended as an alternative for integrated pest management of TRW.