Peach Tree Borer

Peachtree Borer (synanthedon exitiosa) Photo: Judy Gallagher

The adult peach tree borer is a blue-black moth. However, it's the inch long caterpillar larvae that do the damage, boring into the bark at or near the soil level. The first indications of its presence you might notice are small piles of sawdust around the base of the tree. Sometimes a gummy sap oozes from holes. In addition to peach trees, this moth also attacks almond, apricot, flowering cherry, nectarine, and plum trees. Mature trees can tolerate some damage; young trees are most vulnerable. Peach tree borer is mostly a problem in California, but can occur wherever peaches grow.

Controls

• Check trees frequently in spring near the soil line, looking for evidence of borer tunneling. If you find holes, probe them with a stiff wire to kill the caterpillar.
• Spray horticultural oil at high, dormant-season rates once leaves fall.
• Use traps and lures and parasitic wasps.