Chemical Ecology and Management of Bark Beetles in Western Coniferous Forests

Abstract

Volume 4 • Issue 1 • 1000e111 J Biofertil Biopestici ISSN:2155-6202 JBFBP, an open access journal Bark beetles (Coleoptera: Curculionidae, Scolytinae) are a large and diverse group of insects that include several species capable of causing extensive amounts of tree mortality in coniferous forests of western North America. These mortality events are part of the natural ecology of western forests, but the negative impacts of severe outbreaks can be substantial. For about a century, researchers in western North America have studied the biology, ecology, and management of the principle species of tree-killing bark beetles, including Douglas-fir beetle, Dendroctonus pseudotsugae, fir engraver, Scolytus ventralis, mountain pine beetle, Dendroctonus ponderosae, pine engravers, Ips spp., spruce beetle, Dendroctonus rufipennis, and western pine beetle, Dendroctonus brevicomis. Substantial basic and applied research has been executed with the goal of developing effective tools and tactics that mitigate undesirable levels of tree mortality. In the early 20 th century, an emphasis was placed on direct control in hopes of reducing beetle populations and thereby assumedly reducing levels of bark beetle-caused tree mortality. Several methods were developed and employed, principally the felling of infested trees and killing of developing brood through solarization (i.e., placement of infested material in the direct sun, which is often sufficient to kill brood beneath the bark); applications of insecticides; and/or burning of infested hosts. After it became apparent that large-scale implementation of direct control methods was rather ineffective, researchers began to focus on development of silvicultural tactics (indirect control) to reduce the susceptibility of forests to bark beetle infestations.