How to Manage Pests

UC Pest Management Guidelines


Peachtree Borer

Scientific Name: Synanthedon exitiosa

(Reviewed 6/10, updated 6/10, pesticides updated 9/15)

In this Guideline:

Description of the Pest

Gum 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 Valley, are white with brown heads. Adults are clear-winged moths with blue-black bodies having yellow or orange bands across the abdomen. The adult peachtree borer may be found from May 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. If this occurs for several years, the tree may eventually become girdled and die.


Apply insecticides when adults emerge in May and again 6 weeks later. Pheromone traps are available to monitor adult emergence. Insecticides are not likely to kill larvae within the tree but will protect against reinfestation as emerged adults lay new eggs on the trunk. Results may not be evident until the following season.

Common name Amount to use** REI‡ PHI‡
(Example trade name) (conc.) (dilute)
(hours) (days)

Calculate impact of pesticide on air quality
The following are ranked with the pesticides having the greatest IPM value listed first—the most effective and least harmful to natural enemies and honey bees, and the environment are at the top of the table. When choosing a pesticide, consider information relating to air and water quality, resistance management, and the pesticide's properties and application timing. Not all registered pesticides are listed. Always read the label of the product being used.
  (Asana XL) 4.8–14.5 fl oz 2–5.8 fl oz 12 14
  COMMENTS: Apply as a directed trunk and scaffold limb spray. Thorough coverage of trunk and scaffolds is required. In dilute application, do not apply more than 200 gal water/acre at the 5.8 fl oz rate. Highly toxic to bees; do not spray directly or allow to drift onto blooming crops or weeds where bees are foraging.
  (Lorsban Advanced) 3 qt/100 gal 96 (4 days) 14
  COMMENTS: Do not apply more than once per year. Highly toxic to bees; do not spray directly or allow to drift onto blooming crops or weeds where bees are foraging.
** For dilute applications, rate is per 100 gal water to be applied in 300-500 gal water/acre, according to label; for concentrate applications, use 80-100 gal water/acre, or lower if the label allows.
* Permit required from county agricultural commissioner for purchase or use.
Restricted entry interval (REI) is the number of hours (unless otherwise noted) from treatment until the treated area can be safely entered without protective clothing. Preharvest interval (PHI) is the number of days from treatment to harvest. In some cases the REI exceeds the PHI. The longer of two intervals is the minimum time that must elapse before harvest.
# Acceptable for use on organically grown produce.
1 Rotate chemicals with a different mode-of-action Group number, and do not use products with the same mode-of-action Group number more than twice per season to help prevent the development of resistance. For example, the organophosphates have a Group number of 1B; chemicals with a 1B Group number should be alternated with chemicals that have a Group number other than 1B. Mode of action Group numbers are assigned by IRAC (Insecticide Resistance Action Committee). For additional information, see their Web site at



[UC Peer Reviewed]

UC IPM Pest Management Guidelines: Nectarine
UC ANR Publication 3451

Insects and Mites

K. R. Day, UC Cooperative Extension, Tulare County
K.Tollerup, UC IPM Program, Kearney Agricultural Center, Parlier

Acknowledgment for contributions to Insects and Mites:
W. J. Bentley, UC IPM Program, Kearney Agricultural Center, Parlier
R. E. Rice, Kearney Agricultural Center, Parlier

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Statewide IPM Program, Agriculture and Natural Resources, University of California
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