Insects affect knapweed
Dr. Dan Bean, Director of the Colorado Department of Agriculture's Insectary in Palisade, introduces the Russian knapweed gall midge to their new home in Mamm Creek.
July 12, 2011
Insects battle knapweed vegetation in Garfield County
In an effort to find another tool in the box on Garfield County's most invasive noxious weed, Russian knapweed, the county vegetation management team, in cooperation with the Colorado Department of Agriculture's Insectary in Palisade, released 100 gall midges to work on the knapweed. The release site was on County Airport property along Mamm Creek and took place in late May.
This new agent is Jaapiella ivannikovi. It was first released in North America in 2009 in Fremont County, Wyoming. Last year the Insectary successfully reared and raised the Fremont offspring in their facility in Palisade. Jappiella is a gall midge that lays its eggs on the growing tip of the plants causing the plant to form a gall around that growing point. This reduces seed production and plant height.
The Mamm Creek release site was one of the first sites in Colorado chosen by the Insectary to be a new home for the Russian knapweed gall midge.
In 2010, the same property was the ste of a release of 10,000 tamarisk leaf beetles, Diorhabda elongata.
We would like to welcome these new residents to our County and wish them well in their endeavors. We will be checking the site next spring to see how well the gall midges fared through the winter.
Russian knapweed close-up with gall midges at the tip (inside stem)
For more information, please contact Garfield County Vegetation Manager Steve Anthony at 970-625-8601.