Peachtree Borer and Lesser Peachtree Borer

Descriptions of peachtree borers and lesser peachtree borers

Peachtree borer and lesser peachtree borer are caterpillars of clearwing moths (Lepidoptera: Sesiidae). Caterpillars are white to cream colored, wrinkled and have a brown head.

Life cycles of peachtree borers and lesser peachtree borers

Winter is spent as a larva under the bark in the cambium layer.  Adult moths of the lesser peachtree borer emerge from late May through September, while peachtree borers emerge from mid–June to early September.  Egg laying begins soon after emergence and mating and larvae tunnel into the bark to feed until the following summer.

The lesser peachtree borer only establishes in previously wounded bark, including pruning cuts, cankers and previously injured areas.  Eggs of the peachtree borer are deposited around the bases of the trees or on the trunks.

Damage caused by peachtree borers and lesser peachtree borers

Larvae live just under the bark of the tree where they feed on the cambium, the inner bark of the tree.  Larvae feeding in the trunk or branches cause girdling that can result in reduce yield, limb dieback or death of the tree.

Feeding Location:

Peachtree borers live and feed in the trunk of the tree from a few inches above to 6 inches below the soil line. 

Lesser peachtree borers will be found feeding in wounded or injured portions of the trunk or larger branches.  Exuded gum mixed with sawdust like frass forms at feeding sites.  Lesser peachtree borer can only attack areas injured by pruning cuts, cankers or other insects.

Management of peachtree borers and lesser peachtree borers

Maintain tree vigor. Keep trees in a good healthy growing condition by mulching the root zone, watering as needed, and proper fertilization and pruning.

Spray insecticides.  Sprays applied thoroughly to trunk and branches during the adult moth egg laying period will prevent further borer damage but will not cure damage and infestations already inside the tree.  Sprays specifically for peachtree borer usually begin about June 1 and are repeated every 3 weeks for 3 or 4 additional sprays.  Pheromone traps are available to monitor the emergence of adult moths and are used to time sprays.

Mechanical Control.  Occasional borers can be surgically removed by carefully cutting larvae out of infested, bleeding trunks.

Do you live in Iowa and have an insect you would like identified?

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Contact information for each states diagnostic laboratory for U.S. residents.  If you live outside of Iowa please do not submit a sample without contacting the Plant & Insect Diagnostic Clinic.  

Links to this article are strongly encouraged, and this article may be republished without further permission if published as written and if credit is given to the author, Yard and Garden, and Iowa State University Extension and Outreach. If this article is to be used in any other manner, permission from the author is required. This article was originally published on September 13, 2016. The information contained within may not be the most current and accurate depending on when it is accessed.