Project Overview
Commodities
- Nuts: hazelnuts
Practices
- Education and Training: extension, on-farm/ranch research, workshop
- Pest Management: chemical control, integrated pest management, physical control, traps
Abstract:
This project addressed knowledge gaps for management of Chrysobothris mali (Horn), Pacific flatheaded borer, (PFB; Coleoptera: Buprestidae) in Oregon hazelnuts. This native pest is particularly damaging in new plantings of tree crops, and recent expansion of hazelnut acreage in Oregon has resulted in major economic impacts. Very little research has been conducted on this pest. Typically, young hazelnut trees (1-2 year old) are targeted for oviposition by the adult females beetles. Literature suggests that PFB are attracted to stress signals emitted by establishing trees (Burke 1929). Female borers find vulnerabilities in the bark to lay their eggs. After hatching form the egg, larvae create galleries in the cambium beneath the bark, typically near the soil line. They may live in the galleries for one or two seasons. The tunneling can result in girdling the of tree. Trees that survive initial attacks can be severely weakened, risking trunk failure due to wind or nut load. Inadequate knowledge of PFB has resulted in devastating losses of young trees for some growers. The goal of our project was to increase understanding of phenology of PFB and help develop effective management strategies to increase sustainability of the hazelnut industry. Our project had 3 objectives.
Research Objectives:
- Develop phenology data for PFB
- Develop PFB monitoring traps for monitoring.
- Evaluate plant protection strategies against PFB
We were successful in developing phenological data describing the flight period of PFB, which we feel is broadly applicable to western Oregon and can be used to predict when trees will be most susceptible to borer attack. The monitoring strategies we evaluated were relatively unsuccessful, which is similar to past efforts to monitor Chrysobothris spp. with traps. More research is needed to evaluate the effect of trap type, color and potential use of volatile attractants. We were successful in evaluating plant protection strategies and much of the information generated has been incorporated into published plant protection guidelines for hazelnut growers. We were also able to disseminate results through a workshop, on-farm visits, and through presentations, flyers and other means.
Project objectives:
Our objectives were designed to provide the most relevant information for management of PFB in young hazelnut orchards. We prioritized research on borer biology and phenology, monitoring, and plant protection. The research formed the basis for Extension resources provided to the industry and a basis for future research projects.
Research objectives:
- Develop phenology data for PFB. There is no information on when PFB emerge and attack trees. These data act as the foundation for pest management; identifying when PFB life stages are active and vulnerable to management. We were particularly interested in the period when adult borers were present, because this would represent the timing when growers could take measures to protect trees from oviposition or early larval development.
- Develop PFB monitoring traps. There are no known effective monitoring tools to identify PFB populations, and more broadly there have not been effective traps developed for any Chrysobothris species. The development of monitoring traps was improve application timing and limit unnecessary pesticide applications when population counts are below economical thresholds. A sensitive trap could help growers determine if treatments were necessary at all.
- Evaluate plant protection strategies against PFB. We evaluated simple physical trunk barriers, deterrents, systemic insecticides, organic, and reduced-risk insecticides as treatments. Grower implementation of efficient protection strategies will lower farmer cost and limit environmental costs of insecticide use.