Peach Twig Borer
Anarsia lineatella
A small moth whose larvae bore into the tender shoot tips of peach and other stone fruit in spring and tunnel into the fruit later in the season. Shoot feeding wilts and kills new growth on young trees, while fruit feeding leaves a worm and brown frass near the stem at harvest.
🔎 How to spot it
Adult moths are about three tenths to half an inch across with steel gray, lightly fringed forewings. Newly hatched larvae are whitish with a black head, while mature larvae are brown with alternating dark and light bands around the abdomen, a feature that separates them from other stone fruit caterpillars. Wilting or flagging shoot tips in spring are the first clue.
🥀 Damage it causes
Spring and early summer larvae bore into and kill new shoots, causing the tips to flag and wilt, which on young, vigorous trees distorts growth and forces unwanted branching. Later generations feed on the fruit, typically entering near the stem end, leaving frass and a tunnel that ruins the fruit. Shoot strikes that look minor can signal a building population that later attacks the crop.
🛡️ Prevent it
Prune out and destroy wilted, infested shoot tips through spring and summer to remove larvae before they mature. The borer overwinters as a tiny larva in cells under bark in cracks and limb crotches, so a dormant horticultural oil helps smother the overwintering larvae. Keep an eye on nearby unmanaged stone fruit that can reseed the problem.
🧯 If it is already here
The key treatments are well-timed sprays around bloom and shortly after, aimed at the young larvae, using environmentally soft materials such as Bacillus thuringiensis or spinosad in the home orchard. A dormant or delayed-dormant oil, sometimes combined with a labeled insecticide, targets the overwintering stage. Timing to bloom and early larvae matters more than the number of sprays.
💡 Good to know
There can be as many as three generations in a single season, and more in hot regions, so early shoot strikes give way to fruit damage later. The banded mature larva and the shepherds-crook wilting of shoots distinguish it from the clearwing borers that attack the trunk. Bt fits well because it spares bees and natural enemies during bloom.
🌱 Plants it attacks
10 plants in the library can be attacked by this pest
For educational and informational purposes only. Pest control advice is general guidance drawn from university cooperative extension sources; always identify a pest positively and read and follow the label on any product before use, especially around food crops, children, and pets.