Novel trunk trap net designs for the control of Eucryptorrhynchus scrobiculatus (Coleoptera: Curculionidae).

BACKGROUND: Eucryptorrhynchus scrobiculatus is a major pest of tree of heaven, Ailanthus altissima, in China. Damage caused by E. scrobiculatus has increased as beetle populations have expanded. We developed a trunk trap net (TTN) and two modified TTNs, i.e., TTN with a wire ring (TTN-WR) and TTN with a spongy cushion (TTN-SC), and evaluated their ability to capture E. scrobiculatus in plantations of A. altissima.

RESULTS: We obtained significantly higher laboratory weevil recapture rates using the TTN-WR and TTN-SC (i.e., 98% and 95.3%, respectively) than using the TTN (65.3%). In total, 84.8% and 85.8% of marked weevils were captured by the TTN-WR and TTN-SC, respectively, which were 1.52- and 1.54-fold greater than the catch rates using TTN in mark-release-recapture field trials. Similarly, we captured significantly more wild weevils using the TTN-WR and TTN-SC (i.e., 2.02- and 2.03-fold more weevils) than using the TTN. Further field trials showed that the TTN-SC treatment significantly reduced densities of weevils and damage to tree-of-heaven in stands.

CONCLUSION: Our results revealed that the TTN-SC is clearly effective for capturing E. scrobiculatus. TTN-SC may be used as an alternative for E. scrobiculatus management with less or no insecticide. This article is protected by copyright. All rights reserved.