Borers are beetles that commonly attack trees that are suffering from water stress. Both the larvae and adults cause damage and entire trees may be killed.

Prevention/Management

• Select trees that are well adapted to Davis and those that have shown some resistance to the borer.
• Alder, ash, birch, and fruit trees are susceptible.
• Healthy, vigorous trees are less frequently attacked.
• Provide water on a regular basis during dry periods.
• Protect trees from injuries; prune dead or damaged branches.
• Paint young fruit trees with interior white latex paint to prevent sunburn.

Controls

• More toxic: Dursban® (chlorpyrifos) and others.
• Less toxic:

- some beneficial insects (tiny wasp - Avetianella, braconid wasp parasites of the borer larvae)
- see prevention and management