The Park County Weed District is looking for site locations to establish Standard Impact Monitoring Protocol Sites (SIMP). SIMP sites will enable us to capture quantitative data to evaluate the long term effectiveness biological control agents are having on noxious weeds. If you have participated with the Park County Weed District in the past by releasing & collecting insects, or you simply want to learn more about biocontrol and think your property may be a candidate for long term monitoring, please contact the Park County Weed Coordinator. 


What is Biological Control and how can it help in the management of noxious weeds?

Biological Control is the introduction of a known predator on a pest for management. Known, natural predators, will feed on the reproductive parts of the plant, defoliate them, and interfere with their ability to transport nutrients. As a result, the plant population will be suppressed and reduced over time.  


How long does biocontrol take to be effective?

Biological Control can take anywhere from 5 to 30 years to be effective. Environmental variation can enhance or inhibit the success of biocontrol. Patience, biological control monitoring, and multiple biological control releases may be necessary.


What noxious weeds in Montana have approved biocontrol agents?

  • Dalmatian Toadflax
  • Yellow Toadflax
  • Leafy Spurge
  • Knapweed Species (spotted, diffuse, russian)
  • St. Johnswort
  • Canada Thistle


Where can I get biocontrol agents?

You can get biological control agents from private companies, you can participate in collection days with the Montana Biological Weed Control Coordination Project, or you can request to participate in the Park County Cooperative Weed Management Area's biological control cost-share program.