How to Manage Pests
UC Pest Management Guidelines
Scientific name: Synanthedon exitiosa
(Reviewed 3/09, updated 3/09)
In this Guideline:
DESCRIPTION OF THE PEST
Gum and frass exuding from around the base of the trunk is evidence of peachtree borer. Larvae of the peachtree borer, found mainly in coastal areas and in the northern San Joaquin and Sacramento valleys, are white with brown heads. Adults are clear-winged moths with blue-black bodies that have yellow or orange bands across the abdomen. The adult peachtree borer flies during the day and may be found from June to September, with larvae present in the tree the rest of the year. There is only one generation each year.
This wood-boring insect can successfully attack healthy trees. The larval stage bores into the crown and trunk of the tree, and mines the cambial layer, often near the graft union. If this occurs for several years, the tree may eventually become girdled and die. It attacks only the peach rootstock and does not infest the almond scion.
Treatment is rarely needed, but if a severe infestation exists, apply insecticides when adults emerge to help control peachtree borer adults and to kill newly hatching larvae. Pheromone traps are available to monitor adult emergence.
UC IPM Pest Management Guidelines:
Insects and Mites
F. G. Zalom, Entomology, UC Davis