North Central Research Station

Exotic Invasive Forest Insects Research Focus

Our research on exotic invasive forest insects focuses on

Biology, ecology, risk assessment, and prevention

Trapping, detection, and monitoring

Management tools for invasive forest insects

Emerging forest insect pests

Established populations of new exotic invasive forest insects are discovered at an alarming rate in the United States. Some invasive insect species detected in the Eastern United States over the last 15 years include one siricid woodwasp (Sirex noctillo), one buprestid beetle (Agrilus planipennis), three cerambycid beetles (Anoplophora glabripennis, Callidiellum rufipennis, C. villosum), five conifer-infesting scolytid bark beetles (Hylastes opacus, Hylurgops palliatus, Hylurgus ligniperda, Pityogenes bidentatus, Tomicus piniperda), and ten hardwood-infesting scolytid ambrosia beetles (Ambrosiodmus lewisi, Euwallacea fornicatus, Xyleborinus alni , Xyleborus atratus, Xyleborus californicus, Xyleborus glabratus, Xyleborus pelliculosus, Xyleborus pfeili, Xyleborus similis, Xylosandrus mutilatus). Although there is concern with each of the above invasive insects, the Asian longhorned beetle (Anoplophora glabripennis) and the emerald ash borer (Agrilus planipennis) are the two most damaging because they attack and kill apparently healthy trees. USDA APHIS enacted Federal quarantines in areas of the country infested with the Asian longhorned beetle, emerald ash borer, and pine shoot beetle (Tomicus piniperda). Each of the above 20 exotics is either a wood- or bark-infesting beetle likely entered the United States in solid wood packing materials such as crating, pallets, and dunnage.

Several questions arise when a non-native insect is discovered. For example, what tree species will the new exotic insect attack, what type of economic and environmental damage will it cause, how quickly and how far will it spread, what can be used to attract and detect it, and what options are available to control it? USDA APHIS must often decide whether or not to impose a Federal quarantine on a new insect based largely on foreign scientific literature and the professional judgment of APHIS employees and their advisors. This was the situation that APHIS faced when Asian longhorned beetle, emerald ash borer, and pine shoot beetle were first discovered in the United States. In each case, APHIS used the best available data to develop their initial regulations, but additional research findings were urgently needed to help support or modify these regulations, as well as to improve monitoring and control efforts. Although intensive study of those insects for which APHIS does not enact a quarantine may appear to be less urgent than for quarantined insects, this may not be the case. APHIS may decide not to initiate a quarantine because the pest is already quite widespread, there are no obvious control options, or there are no clear movement pathways for the pest that can be regulated. Moreover, the type and severity of impacts potentially caused by newly established insects are often at first difficult to predict. Clearly, there is a lack of understanding of the biology and ecology of exotic invasive forest insects, risk assessment, pathways of entry, and prevention methods; trapping methods, detection techniques, and monitoring strategies for exotic invasive forest insects; and tools for managing invasive forest insects.

These problems are important to a wide array of resource managers, policymakers, industries, and communities, especially when there are programs to formally eradicate, suppress, or regulate potential movement of exotic pests through Federal and State quarantines. The development of improved monitoring and trapping techniques, new detection and control strategies, more effective suppression and eradication programs, and enhanced abilities to identify high-risk exotic pests and pathways. The overall outcome of this research program will be to 1) reduce the number of exotic pests that enter and become established in the United States and 2) lessen the negative impacts caused by those exotic forest pests already established in the United States.