Missoula County Weed District & Extension

Insects

Spurge Bio 1What are Insects and Biological Control?
When we use natural enemies to reduce invasive species populations, we refer to the natural enemies as biological control agents, or sometimes biocontrol agents. Since many serious rangeland weeds are introduced species, they have few established natural enemies on this continent. Biological control can be defined as the use of living organisms to depress the population of a pest. However, biological control could be more accurately called biological suppression, i.e. reducing the population of the target weed to an acceptable level. Often the goal of those who use biological control agents on rangelands is to suppress the alien weeds and at least partially restore the native plant community. It is most effective on dense infestations over large areas.


Click on the noxious weed below for more information on the insects that impact them:

small dalmatiantoadflax
Toadflaxes
 
small leafyspurge
Leafy spurge
 
small spottedknapweed
Spotted 
knapweed 
small stjohnswort
St. johnswort
 

Interested in obtaining insects for your property? Please click here.