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How to identify it
- Mature larvae are chocolate brown with alternating dark and light bands and a black head, up to 1/2 inch long.[1]
- The pale membranes between brown segments set it apart from codling moth and oriental fruit moth larvae.[1]
- Adults are 1/3 to 2/5 inch, dark gray mottled with white, with snoutlike palpi projecting from the head.[1]
- In fall and winter, small chimneys of reddish-brown frass mark overwintering larvae in branch crotches.[1]
Look-alikes
| Look-alike | How to tell them apart |
|---|---|
| Oriental fruit moth | Both cause shoot strikes, but oriental fruit moth larvae bore deep to the pit rather than feeding under the skin.[1] |
| Codling moth | Codling moth larvae also bore deep around the pit, unlike the shallow scars of peach twig borer.[1] |
Where it lives
It's a pest of almond and stone fruits.[1]
Biology and life cycle
Young larvae overwinter in cells under thin bark of 1- to 3-year-old wood, in pruning wounds or bark cracks.[1]
They emerge just before and during bloom and feed on blossoms and shoots; moths appear from late March through May.[1]
Later generations attack twigs or fruit, preferring to feed just under the skin once fruit colors.[1]
Damage and signs
Health risk
It feeds on fruit trees only; UC IPM mentions no risk to people.[1]
Control
Biological control
About 30 kinds of parasitic wasps and predators attack it; protect them by controlling ants and dust and avoiding persistent broad sprays.[1]
Pesticides
Where damage was intolerable, Bt or spinosad applied during bloom is most effective; apply spinosad at petal fall in late afternoon, when bees aren't active.[1]
Alternatively, horticultural oil plus spinosad at the delayed-dormant stage covers shoot tips; oil alone doesn't control it.[1]
More from Utah State University Extension
Northern Utah usually has three generations (May to June, July, and August to September) and southern Utah four or more; later-summer larvae typically enter fruit near the stem end.[2]
Common questions
- What are the little piles of reddish sawdust in my peach tree crotches?
- They're frass chimneys at the openings of overwintering peach twig borer cells.[1]
- When should I treat peach twig borer?
- At bloom with Bt or spinosad, or at the delayed-dormant stage with oil plus spinosad; sprays after petal fall are unlikely to work well.[1]
Sources
- University of California Statewide IPM Program, “Peach Twig Borer (Pests in Gardens and Landscapes).” ipm.ucanr.edu/PMG/GARDEN/FRUIT/PESTS/peachtwigbor.html (accessed 2026-10-06)
- Utah State University Extension, “Peach Twig Borer.” extension.usu.edu/planthealth/research/peach-twig-borer.php (accessed 2026-10-15)
- iNaturalist, “Anarsia lineatella taxon page (order and family).” www.inaturalist.org/taxa/324700 (accessed 2026-10-06)