Studies on Host Preference and its Influence on European Pine Shoot Moth Success and Development

Abstract

The European pine shoot moth (Rhyacionia buoliana (Schiff.)) attacks pine species grown in Michigan for forestry, Christmas tree, and ornamental purposes. Much research has been carried out on life history and direct insecticide control, (Butcher and Haynes 1960; Donley 1960) in efforts to minimize injury. As a result of these studies, practical control methods have been developed for intensively managed stands such as Christmas trees and nursery stock. While the need for a better understanding of shoot moth biology and ecology is generally accepted, the inability of foresters and entomologists to obtain satisfactory shoot moth control with low gallonage insecticide applications under forestry conditions has given impetus to studies on host preference and the influence of the host on shoot moth success and development. Such information, when available, might conceivably suggest planting and management steps that foresters could take in order to minimize attack and injury by this pest in the future. In Michigan, the European pine shoot moth overwinters as a partially grown larva and feeding is resumed about April 20. By late May or early June, pupation takes place in the bud area and adults emerge in about 2 weeks. Eggs are laid on the bark and needles, and hatching occurs within 10 to 15 days. Newly hatched larvae feed at the base of the current year's needles, later moving to the terminal and lateral buds where they remain until the following spring. Pitch blisters or “tents” formed as a result of feeding. in the bud area are useful indicators of shoot moth presence and activity.