Common crops affected
- Peach
- Cherry
- Plum
- Apple
What is it?
Clearwing borer larvae bore beneath the bark at the trunk base, crown and roots, disrupting the tree's vascular flow. The clear-winged, wasp-like adults lay eggs on bark; established borers are hidden under bark, so timing and the soil/crown approach matter.
How to identify it
- Gummy ooze (gummosis) mixed with frass at the trunk base and crown.
- Sawdust-like frass at bark cracks and the soil line.
- Loose, dying bark and girdled, declining trees; sudden collapse in young trees.
- Wasp-like clearwing moths near trunks in summer; pheromone traps confirm flights.
Life cycle & spread
Adults lay eggs on lower trunk/bark; larvae bore in and feed under bark for months (often overwintering as larvae); typically one to two generations per year depending on species and region.
Conditions that favour it
Stressed, wounded or sunburned trunks attract egg-laying; mechanical and pruning wounds and poor tree vigour increase risk.
Damage and how it spreads
Tunnelling girdles and weakens trunks and crowns, reducing vigour and yield and, in young trees, killing them outright.
Monitoring & scouting
Use pheromone traps to time adult flights; inspect trunk bases for gummosis and frass; target egg-hatch and the trunk/crown zone.
How to control it
- Treat the trunk/crown at egg-hatch;
- address crown- and root-zone larvae through the soil;
- protect trees from trunk wounds and sunburn;
- keep trees vigorous.
Recommended Vegalab solution: Larva Control
Larva Control — natural broad-spectrum larvicide (oxymatrine) applied to the lower trunk/crown at egg-hatch to target young larvae before they bore deep under bark. - Larva BioControl — live Steinernema carpocapsae nematodes applied to the moist crown and soil zone to reach borer larvae in the lower trunk, crown and roots.
| Role | Product | Use |
|---|---|---|
| Primary control | Larva Control | |
| Also apply | Larva BioControl |
Preventing it next season
Avoid trunk wounds, protect against sunburn, keep trees vigorous, monitor flights with pheromone traps, and treat at egg-hatch.
Claims and product availability vary by jurisdiction. Always read and follow the product label.