Gary E DATERMAN
Pacific Northwest Research Station. Forestry Sciences Laboratory, 3200
Jefferson Way, Corvallis, OR 97331, USA
The application of pheromones and other semiochemicals for management of forest insects in North Ameiica has steadily increased, although at a inore modest rate than might have been predicted in the 1970's. Currently, an expanding public concern for the environment, a widespread phobia of conventional toxic pesticides, and recent easements in pheromone tegulation policies, appear to suggest a more encouraging climate for future development and use of semioclleinicals. This presentation highlights some of the major pheromone applications currently in use in the United States and Canada. and suggests opportunities for additional applications in the future.
Numerous examples of monitoring forest insects with semiochemical-baited traps can be cited. Monitoring objectives may vary, but are generally for purposes of detecting new infestations (particularly of exotic pest species), detecting presence of a species for purposes of timing control treatments, and for assessing population numbers to evaluate efficacy of treatments or to predict damage potential. Well known detection trapping programs exist for European and Asian gypsy moths across the USA and Canada, with more localized detection prograins in the eastern USA and Canada for the European pine shoot beetle. and in the western USA and Canada for the European pine shoot moth. There is abundant opportunity to increase monitoring programs for forest insects in the future, with the most pressing need for detection programs of additional introduced species such as the browntail moths and other lymantriids, and bark beetles such as the European spruce beetle which could cause devastating damage to spruce forests in Canada and Alaska Detection trapping at ports of entry should be expanded for the species that are known to have high potential for causing damage.
Although singularly impressive, there are fewer examples of successful pheromone treatments for direct control. Degrade of lumber by ambrosia beetles in western Canada has been successf'ully reduced by a widely used trap-out system, on a limited scale, mating disruption has been successful for lepidoptei-an species such as western pine shoot borer, European gypsy moth, and Douglas-fir tussock moth, and, a variety of bark beetle pheromone approaches have been used to prevent damage by use of trap-out or aversion techniques, such as those used for the Douglas-fir beetle, mountain pine beetle, and the southern pine beetle. Many of the bark beetle approaches are as yet experimental and unregistered, but promising results suggest expanded applications in the future. Because both aggregation and anti-aggregation (or aversion) pheromones are available for some bark beetle species, landscape-scale inanipulations may be possible for regulating where beetle activity does or does not occur Direct control by the mating disruption method will improve with development of new dispensers and distribution methods, and possibly by combining with toxicants as an "attract and kill" technology. Pheromone technologies for meeting management objectives will be used selectively to emphasize protection of high-value forest resources such as parks and other recreation sites, special wildlife habitat areas, intensively managed plantations, watersheds, etc.