Biological weed management utilizes insects to aid in the control
of select noxious weed infestations. When used in an Integrated
Weed Management Program, these insects are very effective. Effects
may not be seen as quickly as compared to other methods, but their
long-term influence has proven to be highly beneficial in the fight
against noxious weeds.
are different approaches to biological weed management. The "active"
approach involves physically releasing insects, like the musk thistle
seedhead weevil (left) or flea beetles, on select weed populations.
The Adams County Weed Department has several sites where insects
have been released and their progress carefully monitored.
The "passive" approach takes advantage of the migratory
patterns of beneficial insects. An example that is common in Adams
County is the work of the Painted Lady butterfly.
The Adams County Weed Department has used sheep to assist in the
control of leafy spurge. Nic, the llama was kept with the sheep
to protect them from predators. The grazing location was on a property
along the South Platte River. The sheep grazed the spurge in the
spring, flea beetles emerged during the summer, and a selective
herbicide was applied in the fall. This is an example of an Integrated
Weed Management (IWM) Program. More than one method is utilized
to contain/eradicate large noxious weed infestations.
When dealing with large infestations, there is no "silver
bullet", meaning don't rely on just one method. Whether it
be grazing, insects, or herbicide treatments, you'll observe more
effective results for the long-term when you use all of the tools
in the "toolbox".