Contents: By Damage and Image
European Pine Shoot Moth (EPSM)
A shepherd's crook symptom or distorted tips of pine trees are indications of possible damage from European Pine Shoot Moth, Rhyacionia buoliana (Denis & Schiffermuller). Feeding by the moth larvae in the buds cause the buds to wilt and turn brown. Continued feeding can kill the terminal bud, leaving lateral shoots to bend up, replacing the terminal with a crooked top. In addition to direct damage, nurseries producing pines for sale need to be aware of the regulations that are required for nurseries which ship to California, Montana, and Nevada (See ODA link below).
Host pines include red, Mugho, and ponderosa pine, which may be badly damaged, as well Scotch and Austrian pines.
The adult moths emerge from overwintered pupa within the buds and begin their flights in late May-June in western Oregon. They mate immediately and begin laying eggs at the base of needles, bud scales, and on twigs of the trees. The eggs hatch in seven-ten days. The young larvae spin a small web near the needle sheath and stems then bore into the base of needles where they feed. Later, as the larvae mature,they move into the buds to feed. Larvae remain in the buds to overwinter.
There are some very helpful websites devoted to management
Dept. of Agriculture Regulations for shipping to California, Montana,
EPSM Degree Day Calculator: Scroll to select model from list.
Hoover, Greg. 2004. European Pine Shoot Moth. Penn State Extension. Accessed 10 June 2014
Miller, W., Hastings, A. and V. Carolin. 1970. European Pine Shoot Moth. USDA-Forest Service. Forest Insect and Disease Leaflet No. 59. Revised November 1970).
Original version: <12 February 2004)
Last update <8 August 2019>
Author: R.L. Rosetta, Extension Nursery Integrated Pest Management, Department of Horticulture, Oregon State University/NWREC.