Agriculture: Almond Pest Management Guidelines

Peachtree Borer

  • Synanthedon exitiosa
  • 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.

    Common name Amount per acre REI‡ PHI‡
    (Example trade name) (hours) (days)
    Not all registered pesticides are listed. The following are ranked with the pesticides having the greatest IPM value listed first—the most effective and least harmful to natural enemies, 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. Always read the label of the product being used.
      (Asana XL)* 9.6–19.2 fl oz 12 21
      COMMENTS: Apply as a directed trunk and scaffold limb spray. Thorough coverage of trunk and scaffolds is required.
    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 these two intervals is the minimum time that must elapse before harvest may occur.
    * Permit required from county agricultural commissioner for purchase or use.
    1 Modes of action are important in preventing the development of resistance to pesticides. Rotate pesticides 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; pesticides with a 1B group number should be alternated with pesticides that have a group number other than 1B. Mode of action is assigned by IRAC (Insecticide Resistance Action Committee).
    Text Updated: 08/17
    Treatment Table Updated: 08/17