Pest profile

Lesser Peachtree Borer

Synanthedon pictipes · Lepidoptera: Sesiidae[2]

Lesser peachtree borers attack older stone fruit trees, usually entering through bark wounds.[1]

Lesser peachtree borer moth, a slender wasp-like dark blue moth with clear wings edged in dark scales, on leaves
Lesser peachtree borer moth, a slender wasp-like dark blue moth with clear wings edged in dark scales, on leaves. (c) Patrick O'Brien, some rights reserved (CC BY) — via iNaturalist, CC BY 4.0

How to identify it

  • Adults are slender, wasp-like, dark blue moths with pale yellow markings and clear wings edged in blue-black scales.[1]
  • Gum oozing from the bark, mixed with reddish-brown frass, marks where larvae are feeding.[1]

Look-alikes

Look-alikeHow to tell them apart
Peachtree borerThe peachtree borer hits young trees at or below the soil line; the lesser borer attacks older trees higher up.[1]

Where it lives

It's a native North American pest of peach, cherry, plum, nectarine and apricot.[1]

US map: public records from 30 states since 1990 (GBIF).

Biology and life cycle

Moths fly by day, most actively from 10 a.m. to 2 p.m., in two generations a year.[1]

Females lay about 400 eggs near wounds, and larvae enter through cracks from winter injury, pruning scars or machinery.[1]

Damage and signs

  • Bark peels from damaged areas, inviting other pests and diseases, and branches can be girdled and die.[1]

Health risk

It feeds on trees; UK Extension mentions no risk to people.[1]

Control

Prevention

Prevention is key: once larvae are under the bark, chemical control is usually ineffective.[1]

Pesticides

Sprays are timed to egg hatch, 7 to 14 days after pheromone traps first catch moths.[1]

Common questions

Why is gum oozing from my peach tree?
Gum mixed with reddish-brown frass often marks lesser peachtree borer feeding.[1]
Can I spray borers already under the bark?
Usually not effectively; control focuses on preventing larvae from getting in.[1]

Sources

  1. University of Kentucky Entomology (ENTFACT), “Lesser Peachtree Borer (ENTFACT-213).” entomology.mgcafe.uky.edu/ef213 (accessed 2026-10-06)
  2. iNaturalist, “Synanthedon pictipes taxon page (order and family).” www.inaturalist.org/taxa/232121 (accessed 2026-10-06)

Updated 2026-10-14. Built from sourced records. Spot an error? Tell us.