How to Manage Pests

UC Pest Management Guidelines


Peachtree Borer

Scientific name: Synanthedon exitiosa

(Reviewed 3/09, updated 3/09, pesticides updated 9/15)

In this Guideline:


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.

Common name Amount per acre** REI+ PHI+
(Example trade name) (conc.) (dilute)
(hours) (days)

Calculate impact of pesticide on air quality
Bee precaution pesticide ratings
The following materials are listed in order of usefulness in an IPM program, taking into account efficacy and impact on natural enemies and honey bees. When choosing a pesticide, also consider information relating to environmental impact. 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 21
  MODE OF ACTION: A pyrethroid (Group 3)1 insecticide.
  COMMENTS: Apply as a directed trunk and scaffold limb spray. Thorough coverage of trunk and scaffolds is required.
** 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.
Preharvest interval. Do not apply within this many days of harvest.
* Permit required from county agricultural commissioner for purchase or use.
# Acceptable for use on organically grown produce.
1 Modes of action are important in preventing the development of resistance to pesticides. 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. 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 is assigned by IRAC (Insecticide Resistance Action Committee). For additional information, see their Web site at



[UC Peer Reviewed]

UC IPM Pest Management Guidelines: Almond
UC ANR Publication 3431

Insects and Mites

F. G. Zalom, Entomology, UC Davis
D. R. Haviland, UC IPM Program, UC Cooperative Extension, Kern County
E.J. Symmes, UC Cooperative Extension, Butte County
K.Tollerup, UC IPM Program, Kearney Agricultural Center, Parlier

Acknowledgment for contributions to Insects and Mites:
C. Pickel, UC IPM Program, UC Cooperative Extension, Sutter and Yuba counties
W. J. Bentley, UC IPM Program, Kearney Agricultural Center, Parlier
R. A. Van Steenwyk, Insect Biology, UC Berkeley
R. E. Rice, Kearney Agricultural Center, Parlier
L. C. Hendricks, UC Cooperative Extension, Merced County
R. L. Coviello, UC Cooperative Extension, Fresno County
M. W. Freeman, UC Cooperative Extension, Fresno County

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