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More than 400 species of exotic (nonnative) forest insects are established in the United States. Among these are several species whose life-history attributes allowed them to become invasive and thereby spread rapidly to cause significant economic and ecological impacts to the Nation's forest and urban trees.

Exotic invasive forest insects can build quickly to damaging levels once established in a new country because they typically arrive with few or none of their natural biological control agents and the trees in the new country often lack evolved defenses against these new arrivals.

Research

Biology, ecology, risk assessment, and prevention

We are conducting several long-term studies on the Asian longhorned beetle (ALB) and pine shoot beetle (PSB), but our primary focus is now on the emerald ash borer (EAB), which was discovered in Michigan and neighboring Ontario in the summer of 2002. It has since been found in Ohio. A Federal quarantine against EAB has been implemented in the United States and major suppression and eradication activities are being carried out in both the United States and Canada. Several studies are underway on the biology and ecology of EAB , including host range, seasonal development, within-tree attack pattern, dispersal, relationship between environmental stress and tree susceptibility to attack, host plant resistance, and impact on forest stand composition and biodiversity. Research is also being conducted to detect key pathways by which various groups of exotic invasive forest insects enter the United States and to identify species that are of quarantine significance to the United States but not yet established in the United States.

Trapping, detection, and monitoring

Recent research has focused on attractants and repellents for PSB, acoustic detection technology for ALB larvae, and development of optimal monitoring strategies for exotic scolytids. These studies led to the development of an optimal lure to attract PSB, identification of key repellents for PSB, and a field-portable acoustic detector for ALB larvae. Work on developing optimal monitoring strategies for several exotic scolytids will continue. Our scientists are working to identify the key attractants for EAB, Hylurgops palliatus, Hylurgus ligniperda, and selected exotic ambrosia beetles. We also are studyig the most effective trapping method for EAB adults.

Management tools for invasive forest insects

For more than a decade, our research focused on management of several invasive forest insects including cultural and chemical control of PSB, microbial control of gypsy moth, and chemical control of ALB and beech scale. Part of this research led to PSB best management practices in the Christmas tree, nursery, and logging industries; basic and applied knowledge on Entomophaga maimaiga, a fungus that attacks gypsy moth, and its role in suppressing gypsy moth populations in North America; and insecticide guidelines for eradicating the ALB and managing beech scale.

Emerging forest insect pests

Due to the increase in international trade, new exotic forest insects are arriving more frequently. Many of these insects live in the wood used to manufacture, package, and ship products from foreign countries to the United States. After arrival at our ports, shipping containers are transported to warehouses throughout the country, and live insects are known to emerge from these containers and warehouses; non-native insects also emerge from imported plants or manufactured goods after purchase at retail stores. Should these insects escape, they can become established and spread rapidly in the Nation's forests and urban trees. Under the right conditions, they become abundant and destructive due to a lack of natural enemies and innate tree defenses. The transport of infested wood and nursery stock also can facilitate the spread of these exotic pests. Estimated economic losses to invasive forest insects in the United States totals $4 billion dollars annually, and the loss of our trees takes an immeasurable toll on the ecology, biodiversity, and aesthetics of our environment.

More Information

This site is under development as the Forest Service brings together the Northeastern and North Central Research Stations to form the Northern Research Station, serving the Northeast and Midwest. Check back often as we expand our site to reflect our combined commitment to supporting the natural resources and people of the Northeastern and Midwestern United States.

For more details about our research visit http://www.ncrs.fs.fed.us/4501/