Field Identification
A clearwing moth whose larvae bore in the trunks and scaffold limbs of peach, plum, cherry, apricot, and other stone fruit, especially at graft unions, pruning wounds, and bark injuries. Frass mixed with gum exudes from holes; chronic attack girdles wood and kills limbs. Closely related in habits to peachtree borer but often focuses slightly higher on trunks and wounded tissue. Occurs across temperate stone-fruit regions of North America—roughly zones 5–9—wherever Prunus orchards and backyard trees accumulate sunscald and mechanical damage.
Adult moths mimic wasps, with dark forewings and yellow-banded abdomens; larvae are cream-colored caterpillars with a dark head, found under bark. Emergence holes are oval; sawdust-like frass distinguishes borer activity from bacterial ooze. Peak flight often runs late spring through summer depending on latitude and heat units.
How to Deal With It
Organic Control Methods
Entomopathogenic nematodes (Steinernema spp. and Heterorhabditis spp.) injected or sprayed into active borer galleries can kill larvae when moisture is adequate and temperatures stay within product ranges. Surround kaolin on trunks may deter egg-laying where labels allow. Repeat nematode applications after irrigation or rain per supplier guidance—timing matters more than brand loyalty.
Braconid and ichneumonid parasitoids attack clearwing larvae in some regions; woodpeckers probe galleries. Keeping orchard floors flowering supports parasitoid adults. Avoid broad-spectrum sprays on trunks during peak flight if alternative tactics are available.
Paint trunks white or use tree guards to reduce sunscald that precedes infestation; avoid mower and string-trimmer strikes. Prune in dry weather and do not leave stubs that heal slowly. Remove severely infested scaffold branches during dormancy and burn or chip on site where regulations allow.
Wire or flexible probe to crush larvae in accessible galleries when detected early—labor-heavy but effective on backyard trees. Traps baited with commercially available lesser peachtree borer lures monitor flight for timing nematode or trunk sprays of approved materials.
Walk orchards monthly in summer, feeling for gum spots and frass. Map trees with repeat attacks for priority painting and guard maintenance. Train crews to flag damage at harvest when foliage is thin and holes are visible.
Let Nature Handle It
Natural Enemies
- Braconid Wasps
- Ichneumonid Wasps
- Woodpeckers (Picidae)
- Entomopathogenic Nematodes
Threat Map