2012 Annual Report
1a.Objectives (from AD-416):
Objective 1: To determine the effects of stress factors on woody ornamental susceptibility to ambrosia beetle attack. Objective 2: To characterize the interactions between ambrosia beetle seasonal incidence, plant stress factors, environmental and phenological parameters in relation to ambrosia beetle attacks. Objective 3: Screen insecticide and repellent biopesticides after ‘stress factors’ that predispose trees to attack have been identified.
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. Understanding the impacts of environmental and management-related stressors on the attractiveness of nursery stock to X. crassiusculus will provide critical information for predicting, avoiding and managing ambrosia beetle attacks. Furthermore, characterizing the efficacy of biopesticides will lead to improved management tactics and a reduction in user and nontarget exposure. The objectives of this proposal are to determine the effects of stress factors on woody ornamental susceptibility to ambrosia beetle attack, to characterize the interactions between ambrosia beetle seasonal incidence, plant stress factors, environmental and phenological parameters in relation to ambrosia beetle attacks, and to screen insecticide and repellent biopesticides after ‘stress factors’ that predispose trees to attack have been identified. To address the objectives, a variety of stress factors common to production nurseries will be evaluated using potted trees and attacks will be monitored. Attractant baited traps will also be used to monitor seasonal flight activity of ambrosia beetle species, and a climatic data logger will also be used to correlate activity with air temperature, rainfall, humidity, and sunlight. Tree phenological characteristics will also be monitored, including dormancy break on experimental trees and other common production nursery plants in the area. Ambrosia beetle flight activity will be contrasted with weather data, tree attack data, and tree phenological data. After treatments have been identified that consistently trigger ambrosia beetle attacks, stress treatments will be applied to trees in order to evaluate insecticides and repellents.
The cooperator conducted research on correlating ambrosia beetle flight activity with environmental and plant phenological parameters. Collaborative research with ARS scientists was conducted into developing optimal trap attractants for detecting and monitoring ambrosia beetles. The efficacy of conventional insecticides and plant-based essential oils for managing ambrosia beetles was also examined. The antiaggregation pheromone verbenone was also screened for repelling ambrosia beetles, which could be used in conjunction with the attractive traps as part of a push-pull system. 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.