1a.Objectives (from AD-416)
Objective 1: Investigate novel interception strategies by deploying attractant-baited traps as a threshold between commercial nurseries and the overwintering woodlots of Xylosandrus crassiusculus and X. germanus.
Objective 2: Optimize trapping as a monitoring and mass trapping tool for ambrosia beetles.
Objective 3: Develop a push/pull strategy for ambrosia beetle pest management by screening repellents and attractants.
1b.Approach (from AD-416)
Exotic ambrosia beetles belonging to the subfamily Scolytinae are increasingly being recognized as key pests of field-grown nursery crops. The granulate ambrosia beetle, Xylosandrus crassiusculus, has become a significant pest of ornamental nursery crops stock since accidentally being introduced into the U.S. from Asia. Studies aimed at improving monitoring and detection techniques are necessary for predicting attacks and closely timing insecticide applications with the flight activity of X. crassiusculus. Experiments on repellents and attractants could also be used to develop a “push-pull” management strategy, whereby ambrosia beetles are “pushed” or repelled away from vulnerable nursery stock and “pulled” or attracted into destructive traps. The objectives of this proposal are to investigate novel interception strategies for X. crassiusculus, to optimize trapping as a monitoring and mass trapping tactic, and to develop a push/pull strategy for use in the nursery agroecosystem. Traps will be deployed to test potential volatile attractants for X. crassiusculus, which will be correlated with environmental data. Trap trees will also be developed for testing repellents, reduced-risk insecticides, and mass trapping purposes.
The cooperator/scientist from Virginia Poly Institute & State University (VT) continued to investigate improved detection and management strategies for ambrosia beetles attacking ornamental nursery stock. Collaborative research was conducted with ARS scientists from Wooster, Ohio into developing a trap tree strategy for detecting and monitoring ambrosia beetles. Results from the VT scientist’s research indicate that deploying ethanol-injected trees is a viable strategy to reduce ambrosia beetle attacks and eliminate the need for pesticide treatments to manage these pest species. Additional studies were conducted to determine the ideal concentration of ethanol for injection purposes, along with the interaction between host species and attractiveness following ethanol injection. The VT scientist also assessed the ability of the repellent compound verbenone to reduce ambrosia beetle attraction to vulnerable nursery stock. The influence of flood-stress on the attractiveness and susceptibility of ornamental trees to ambrosia beetles was also assessed.
This research relates to the following objectives of the parent project: (1) to reduce, through knowledge generated by research, crop losses and damage caused by insect pests of ornamental nursery crops, turf, and other horticultural crops; (2) to develop alternative management strategies for pest control that will reduce dependence upon traditional uses of insecticides, and lessen impact on groundwater.
The authorized departmental officer's designated representative (ADODR) maintained frequent contact via e-mail and telephone conversations with the VT scientist to monitor progress of the research project, along with a site visit to the cooperator’s facility and stakeholders. The VT scientist also attended an ambrosia beetle organization meeting led by the ADODR at the annual meeting of the Entomological Society of America.