Peach Twig Borer

Anarsia lineatella

The peach twig borer damages stone fruits by feeding in new shoots and under the skin of fruit. Larvae emerge in early spring, feeding on fresh leaves and shoots until the shoots begin elongating. Once this occurs the larvae bore into the shoots, causing them to die back (shoot strikes or flags). This flagging can cause an increase in undesirable lateral branching. Overwintering adults emerge later, usually around April-May, with the first generation of larvae forming a second flight in late June to early July.

Controlling peach twig borers completely can be difficult, but there are a number of steps you can take to minimize their numbers and damage to the trees.

  • Mating disruption with Scentry PTB Spirals can be done by placing the spirals a few days before blossom. Replace spirals every 3-4 weeks.
  • Surround WP (kaolin clay) may help deter larvae from feeding and adults from laying eggs.
  • Btk sprays can be applied to plant surfaces to kill larvae as they feed prior to entering the shoots.