Skip to Main Content
U.S. Forest Service
Caring for the land and serving people

United States Department of Agriculture

Home > Search > Publication Information

 Due to a lapse in federal funding, this USDA website will not be actively updated. Once funding has been reestablished, online operations will continue.


  1. Share via EmailShare on FacebookShare on LinkedInShare on Twitter
    Dislike this pubLike this pub
    Author(s): Yvette K. OrtegaDean E. PearsonKevin S. McKelvey
    Date: 2004
    Source: Ecological Applications. 14(1): 241-253.
    Publication Series: Scientific Journal (JRNL)
    Station: Rocky Mountain Research Station
    PDF: View PDF  (276.0 KB)

    Description

    Exotic insects are commonly introduced as biological control agents to reduce densities of invasive exotic plants. Although current biocontrol programs for weeds take precautions to minimize ecological risks, little attention is paid to the potential nontarget effects of introduced food subsidies on native consumers. Previous research demonstrated that two gall flies (Urophora affinis and U. quadrifasciata) introduced for biological control of spotted knapweed (Centaurea maculosa) dramatically affect the foraging ecology of the deer mouse (Peromyscus maniculatus), a native generalist predator with important trophic linkages. In the current study, we found that relative abundance of deer mice was elevated twofold in grassland habitats with high densities of spotted knapweed and gall fly food sources, compared to those dominated by native vegetation, in two of three years. Availability of gall fly larvae during the critical overwinter period appeared to reduce overwinter population declines of mice in knapweed-invaded habitats. These positive effects on populations apparently overshadowed negative effects on breeding productivity associated with knapweed invasion and loss of the gall fly resource during the summer. Our results suggest that insect biocontrol agents can subsidize native consumer populations, setting the stage for various indirect effects on food webs. Comprehensive understandings of the conditions under which introduced biological control agents may exhibit nontarget effects on native food webs are needed to further develop criteria for screening potential biocontrol agents before they are released.

    Publication Notes

    • You may send email to rmrspubrequest@fs.fed.us to request a hard copy of this publication.
    • (Please specify exactly which publication you are requesting and your mailing address.)
    • We recommend that you also print this page and attach it to the printout of the article, to retain the full citation information.
    • This article was written and prepared by U.S. Government employees on official time, and is therefore in the public domain.

    Citation

    Ortega, Yvette K.; Pearson, Dean E.; McKelvey, Kevin S. 2004. Effects of biological control agents and exotic plant invasion on deer mouse populations. Ecological Applications. 14(1): 241-253.

    Keywords

    biological control agents, Centaurea maculosa, deer mice, exotic plants, food subsidies, spotted knapweed, Lolo National Forest, Montana, USA, nontarget effects, Peromyscus maniculatus, Urophora spp.

    Related Search


    XML: View XML
Show More
Show Fewer
Jump to Top of Page
https://www.fs.usda.gov/treesearch/pubs/48039