2023 Peach Twig Borer

2023 Peach Twig Borer

Landscape & Garden    Treasure Valley, Treasure Valley - Idaho

2023 Peach Twig Borer

Posted on: May 31, 2023 by Ruth Givens

It is time for management of the peach twig borer, based on degree days. This pest is a concern for those growing peach, nectarine, apricot, plum and prune. Adult moths are 0.3 – 0.5 inches long, with light and dark gray mottled wings. Scales on the front of head cause the head to appear pointed. The larva is a caterpillar, about 0.5 inch long, with a dark brown head and distinctive, alternating light and dark bands on the body.  

Larvae injure fruit trees by feeding on the buds and twigs early in the season, then the larvae bore into the shoots, causing a characteristic "flagging" or wilting of the new growth. Later generations of larvae feed within shoots or even on the fruit itself. Flagging of twigs indicates an infestation. 

For chemical control management options review the PNW Handbook link below to select a control option appropriate for operation. Apply according to label directions. 

For cultural controls prune out shoot strikes in the late spring and early summer as soon as they are detected to prevent these larvae from completing development and contributing to summer generations of the pest. If old shoot strikes are observed during pruning in late winter to early spring, plan to apply early season controls. Old strikes hold onto the dead leaves and appear as “flagged” terminals. 

https://pnwhandbooks.org/insect/tree-fruit/peach-nectarine/peach-nectarine-peach-twig-borer 

https://climate.usu.edu//includes/pestFactSheets/Peach-Twig-Borer.pdf