GovernmentDepartmentsOnline ServicesExploreHow Do I - Help Center
Click to Home
Biological Insect Releases
Biological Controls (insects) are helping to control infestations of several invasive and noxious weed species found in Cowlitz County.

Biological insects are approved for release by the Federal government and are moved around in our state through the Washington State Department of Agriculture and the King County WSU Extension office in a coordinated effort with each county Noxious Weed Program in the state of Washington.

Releases prior to 2009
•Tansy ragwort  •Purple loosestrife  •Canada thistle 
•Scotch broom

2009 and 2010 Releases

•Dalmatian toadflax  •Meadow knapweed 
•Diffuse knapweed  •Spotted knapweed

A total of seven host-specific biological control insects have been released to control the noxious weeds listed above. Other biological insect species that were released
throughout Washington State have also found their way into our county to help fight infestations.

In 2009 alone, five target-specific species (1800 insects) were released.

2011 and 2012 Releases
•Dalmatian toadflax  •Meadow knapweed 
•Diffuse knapweed  •Spotted knapweed  •Scotch broom

Dalmatian toadflax beetle

Diffuse knapweed beetle 

Meadow knapweed insects

Noxious Weeds - Click Here To Go Back To Noxious Weeds

Go To Search