2010 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.
Cooperator continued to evaluate the influence of abiotic stress factors on predisposing nursery stock to attacks by ambrosia beetles. Research also focused on correlating flight activity with environmental and phenological parameters, which will ultimately assist with improving the timing and reducing the frequency of insecticide applications. Collaborative research was conducted with ARS scientists into developing a trap tree strategy for detecting and monitoring ambrosia beetles. Cooperator also determined the efficacy of conventional insecticides and environmentally-friendly botanical insecticides for reducing attacks by ambrosia beetles. The ADODR maintained frequent contact via e-mail and telephone conversations with the cooperator to monitor progress of the research project. ARS scientist also organized and led a discussion of ambrosia beetle research progress that took place at the annual meeting of the Entomological Society of America.