Montana Field Guide

The Eurasian Pine Shoot Beetle (aka Common Pine Shoot Beetle) is a species of bark beetle native to Europe, Asia and Africa. It was introduced to North America and first detected in Ohio in 1992 (Haack and Kuccera 1993). The species is a pest of pine trees and can damage to new shoots and stress with mortality of host trees in extreme cases. The species is currently found across the northeastern and northcentral regions of the United States and associated Canadian provinces.

Adults are small brown or black beetles ranging in length from 3.5 to 4.8 mm in length and could be confused with beetles in the genus Dendroctonus. It can be separated from these by the presence of six antennomeres composing the funicle of the antenna. The species is separated from other members of its genera by the smooth second elytral interval on the declivity (Thomas and Dixon 2010).

The Pine Shoot Beetle is capable of infesting species of pine (Pinus) and to a lesser extent spruce (Abies) and larch (Larix). The species is capable of exploiting dead or dying timber which may increase abundance with impacts on live healthy trees in the immediate area (GISD 2019). In North America the species is capable of colonizing many species of native pines (Siegert and McCullough 2003).

The primary host trees of this species are pines (Pinus) but they will colonize spruce (Abies) and larch (Larix) as well (Siegert and McCullough 2003).

Pine Shoot Beetles deposit eggs in the early to mid-spring within galleries the females construct within the inner bark and outer sapwood of dead wood, with preference to fresh cut stumps and slash. Live trees may also be colonized. Upon hatching, larvae feed horizontally under the bark. In late spring and early summer these larvae pupate and emerge as adults. Newly emerged adult beetles fly to the new shoots of healthy trees, and begin feeding on the inside of these lateral shoots. As the adult matures it is capable of destroying 1-6 shoots. Adults overwinter within the bark at the base of pine trees. Spring emergence is dependent on temperature and typically during periods that reach 10-12 C. Breeding flights begin after emergence (Thomas and Dixon 2010, GISD 2019).

In contrast to many forest pest species, the adult Pine Shoot Beetle is more destructive than the larval stage. Through destruction of new growth, the beetle can reduce general health of trees and predispose the tree to attack by other pest species (as reviewed in GISD 2019). The beetle may also introduce blue stain fungus (Leptographium spp., Gibbs and Inman 1991), which are pathogenic to pines (Jacobs et al. 2004).

There are no known treatments practical for control of this species. The USDA has instituted a quarantine of wood products that may contain the species (USDA 2016). Also forestry practices such as debarking trees and managing dead timber and untreated timber products can decrease prevalence (GISD 2019).

For information and resources on plant pests and diseases see the USDA's Animal and Plant Health Inspection Service's Plant Pests and Diseases Profiles