July 8, 2005
Regional Integrated Weed Management Activities
Weevils, part of a biological war on weeds, were released on 29 June on McMillan Mesa near the USGS laboratory, onto Centaurea diffusa, known as Diffuse Knapweed, to create an "Insectary" colony, one of several seeded over the next several days. Over 500 hungry weevils, both Larinus obtusus and L. minutus were released at each site within the city. These are considered intermediate size releases into small-to-intermediate size Knapweed colonies. Since we are releasing to an intermediate-to-large number of sites, we hope to have a high probability of successfully achieving persistent insectary colonies in the next few years. The weevils were provided by USDA-APHIS, who also approved the release permit and participated in the release, along with the Coconino County Extension Service and the City of Flagstaff Parks and Recreation Division.
In this photo, Genus Larinus weevils are released from their shipping container onto a colony of Diffuse Knapweed at a release site within Flagstaff. The weevil adults, about the size and color of a watermelon seed, will soon warm up and disperse to other plants.
Similar releases are being conducted at this time with insects intended to provide biological control of Dalmation Toadflax in Coconino National Forest, with a team of weed specialists including USDA-APHIS again, and USFS/Coconino National Forest botanists. If these insectaries succeed, the benefits of control should extend throughout Coconino County.
Parks and Rec Maintainer Steve Zimmerman(L) and Superintendent Felipe Garcia (R) releasing genus Larinus weevils onto a colony of Diffuse Knapweed, Centaurea diffusa, that has smothered a meadow at a site within Flagstaff. By releasing two species at each of several sites, chances of establishing a successful colony are increased, saving time and money.
Parks and Rec Maintainer Steve Zimmerman (L) and Superintendent Felipe Garcia (R) check to see that all of the 550 weevils in this shipping container have been released onto the colony of Diffuse Knapweed that has smothered extensive portions of this meadow within Flagstaff. City, County, State, and Federal agencies work together through the San Francisco Peaks Weed Management Area to coordinate the war on invasive plant pests.