An official website of the United States government.

Official websites use .gov
A .gov website belongs to an official government organization in the United States.

Secure .gov websites use HTTPS
A lock ( ) or https:// means you've safely connected to the .gov website. Share sensitive information only on official, secure websites.

Biological Control of Arthropod Pests and Weeds


<OL> <LI> Characterize and evaluate the effect of established natural enemies. <LI>Exploration, importation, and assessment of natural enemies for invasive pests. <LI> Implementation, evaluation, and enhancement of biological control. <LI>Evaluate the benefits and risks of natural enemies. </ol>Expected Outputs: Natural enemies of selected insect pests and weeds will be identified in other countries, tested, and pursued as potential biological control agents. Host range limits of introduced biological control agents across geographical areas will be identified. Regional cooperation will be strengthened. Discovery of effective natural enemies that are adapted to climatically different regions. More effective integration of biological control in pest management stystems will be achieved in the region. Documentation of the geographic spread of introduced biological control agents. Determination of the need for new natural enemies or other technologies basesd on informed evaluations. The quantification of the impact of introduced and native natural enemies, and their impact on non-target organisms, will permit the development of biologically-based IPM programs.

More information

NON-TECHNICAL SUMMARY: The growing emphasis on environmental and food safety issues has intensified interest in the development of biological controls as a means for controlling pests. The effective use of natural enemies in biological control programs is contingent upon understanding their ecology and that of their targets, their interaction with production practices, and the most effective means of using them. Sporadic invasions by exotic pest species disturb existing IPM programs and continue to pose threats to American agriculture and well being, making continued efforts in importation biological control relevant and necessary. At the same time, target and non-target effects of these introductions must be documented to assure the continued value and safety of importation biological control. Resident populations of natural enemies do not always provide adequate levels of pest suppression. In such circumstances, it may be necessary to release native or introduced natural enemies. Success of this option, however, is dependent on effective production, distribution, and release technologies for the natural enemies to be so used. This project addresses each of the aspects of biological control noted above and places them in the overall context of the Southern Region. Expected outcomes/impacts of this project are numerous. For example, effective production, distribution, and release technologies for natural enemies of invasive pests will be developed, enhanced, and improved; these technologies will be implemented by state and federal labs. Biological control measures for new invasive species of insects and weeds will be developed and transferred to the end-user by extension personnel. Improvements in classical biological control strategies will be developed that will be accepted by regulatory and environmental communities, as well as the general public. Biologically-based IPM programs, including cultural control, will be developed and accepted to maximize the effectiveness of natural enemies on invasive species of insects and weeds.

APPROACH: Project participants will meet annually to refine research coordination. Quantitative evaluation of introduced natural enemies on target species will be accomplished using established manipulative experiments that incorporate accepted elements of experimental design, replication and statistical analyses. Effects of introduced biological control agents on target organisms will be separated from other sources of variation by comparing biological control treatments to experimental units, e.g., cages or plots, where biological control organisms have been excluded mechanically, chemically or biologically. Post-release monitoring programs will focus on state or federally listed threatened and endangered species (thistle species). Insect and weed biological control researchers will collaborate during the screening of natural enemies of insect pests to ensure they will not attack established or candidate weed biological control agents. Foreign exploration and surveys will be conducted cooperatively to identify biological control agents in the home range of the pest species. Promising natural enemies will be imported into quarantine facilities in the region for pre-release risk assessment and evaluation of production and biological characteristics. Risk assessment for weed control projects will follow the guidelines established by the Technical Advisory Group (TAG) for Biological Control of Weeds. Risk assessment for projects with arthropod targets will include host range studies, screening for pathogens, and evaluation of potential interference between arthropod and weed pest biocontrol agents. Only those natural enemies that have undergone risk assessment will be released from quarantine. Teams of scientists working within the project will coordinate releases from quarantine and distribution of biological control agents. For natural enemies to be used effectively and efficiently in pest management systems, researchers must have a better understanding of how indigenous natural enemies affect the population dynamics of pest species. The role of existing natural enemy complexes in reducing pest populations must be explored thoroughly. Studies will measure host/prey suppression by natural enemies in selected commodities and assess the effect of existing natural enemies on the efficacy of introduced biological control agents. Projects will focus on hemlock woolly adelgid, elongate hemlock scale, and musk thistle, and their associated introduced and native natural enemies.

Grant, Jerome
University of Tennessee
Start date
End date
Project number
Accession number