Classical biological control for the protection of natural ecosystems

Authors: VAN DRIESCHE, R - University Of Massachusetts; Carruthers, Raymond; Center, Ted; HODDLE, MARK - University Of California; HOUGH-GOLDSTEIN, JUDITH - University Of Delaware; MORIN, L - Commonwealth Scientific And Industrial Research Organisation (CSIRO); Smith, Lincoln; WAGNER, D - University Of Connecticut; Fuester, Roger; Goolsby, John; Pemberton, Robert; Pratt, Paul; Rayamajhi, Min; Tipping, Philip

Submitted to: Biological Control
Publication Type: Peer Reviewed Journal
Publication Acceptance Date: 6/1/2010
Publication Date: 8/11/2010
Citation: Van Driesche, R.G., Carruthers, R.I., Center, T.D., Hoddle, M., Hough-Goldstein, J., Morin, L., Smith, L., Wagner, D.L., Fuester, R.W., Goolsby, J., Pemberton, R.W., Pratt, P.D., Rayamajhi, M.B., Tipping, P.W., et al. 2010. Classical biological control for the protection of natural ecosystems. Biological Control. 54(SUPPL. 1):S2-S33.

Interpretive Summary: ' Biological control of insects and weeds has provided substantial benefits to natural ecosystems. This article reviews biological control in natural areas because most reviews have been done for agricultural ecoystems. A current review of biological control programs shows increased research activity in program directed at natural ecosystems. This increased emphasis underscores the usefulness of biological control in restoring ecosystems which include, forests, grasslands, and wetlands.

Technical Abstract: We review the contribution, at a world level, of classical biological control of invasive insects and plants to the preservation of wildlands, including their biodiversity, their natural resources, and the ecosystems services that they provide. We include both older projects with demonstrated benefits and, to highlight current activity, selected new projects of importance that are in early stages of development. In total we consider 70 projects, selected by authors based on their knowledge of biological control projects that have targeted pests damaging to natural ecosystems. It is important to note that the list of projects covered, while considerable, is not comprehensive. Of the cases reviewed, we found fewer projects against insect targets (21) than against invasive plants (49), in part because many insect biological control projects were carried out against agricultural pests, while nearly all projects against plants targeted invasive plants in natural ecosystems. Of the 21 insect projects reviewed, 81% (17) provided benefits to protection of biodiversity, while 48% (10) protected products harvested from natural systems, and 5% (1) preserved ecosystem services, with many projects contributing to more than one goal. In contrast, of the 49 projects against invasive plants, 98% (48) provided benefits to protection of biodiversity, while 47% (23) protected products, and 25% (12) preserved ecosystem services, again with many projects contributing to several goals. We classified projects into complete control (pest generally no longer important), partial control (control in some areas but not others), and “in progress,” for projects in development for which outcomes do not yet exist. For insects, of the 21 projects discussed, 59% (13) achieved complete control of the target pest, 18% (4) provided partial control, and 41% (9) are still in progress. By comparison, of the 49 invasive plant projects considered, 27% (13) achieved complete control, while 33% (16) provided partial control, and 47% (24) are still in progress. For both categories of pests, some projects’ success ratings were scored twice when results varied by region. We found approximately twice as many projects directed against invasive plants than insects and that protection of biodiversity was the most frequent benefit of both insect and plant projects. Ecosystem service protection was provided in the fewest cases by either insect or plant biological control, but was more likely to be provided by projects directed against invasive plants, likely because of the strong effects plants exert on landscapes. Rates of complete success appeared to be higher for insect than plant targets (59% vs 27%), perhaps because most often herbivores gradually weaken, rather than outright kill, their hosts, which is not the case for natural enemies directed against pest insects. For both insect and plant biological control, nearly half of all projects reviewed were listed as currently in progress, suggesting that the use of biological control for the protection of wildlands is currently very active.