Field Bindweed is prevalent within Nez Perce County’s rangelands, roadsides, pastures, recreation lands, and cropland.

CONTROL

Since 2013, the District has assisted landowners in releasing bio-control agents to control field bindweed. The goal of this effort was to ensure that there was a sufficient population of the insects to provide a sustainable control level.

There is one insect approved for release in the State of Idaho. The District focuses on the release of the Field Bindweed Gall Mite, Aceria malherbae. The adults feed on upper leaf surfaces – causing them to distort and curl tightly inward.

Figure 1. Field bindweed gall mite (Aceria malherbae). The microscopic biocontrol agent for field bindweed. Photographer USDA Agriculture Research Service Archive, USDA Agricultural Research Service, Bugwood.org

Figure 2. Damage to young field bindweed plant, caused by gall mite. Photographer Bob Nowierski, Montanta State University, Bugwood.org.

Partners and Funding

The District works closely with the Nez Perce Bio-Control Center to coordinate release site locations and obtain staff training. In addition, release site locations are transmitted to the Nez Perce Bio-Control Center as part of a regional database.

This project was funded through the Bonneville Power Administration’s Fish and Wildlife program and the Idaho State Department of Agriculture’s Noxious Weed Program. The Bonneville Power Administration provides funding to the District for steelhead habitat restoration. The bio-control releases are a component of the Lapwai Creek restoration plan’s objective of reducing noxious weeds within the watershed. The Idaho State Department of Agriculture’s Noxious Weed program funds are prioritized through the Clearwater Basin Cooperative Weed Management Area.

2013 Activities

2,400 insects were released at two sites within the county. The 2013 releases are estimated to impact 10 acres of field bindweed. Figure 3 illustrates the 2013 release locations.

Bio-Control Summary of Activities - 2013

Figure 3. 2013 Field Bindweed Bio-Control Releases.