Land owners and managers who are interested in managing leafy spurge populations on specific areas can get good advice from local county weed managers (contact info below)—they are your best first contact as you move forward with your weed management plans.
Moffat County Weed & Pest
Jesse Schroeder, Pest Management Manager
New herbicides come on the market from time to time—county weed managers are often the first to try them in various settings and/or in combination with other herbicides, grazing programs, cropping systems, or biocontrol. It can sometimes be advantageous to use more than one technique to meet management goals within budget constraints. If owner/managers are interested in trying biological control, county weed managers can help directly, or they may refer you to the Colorado Department of Agriculture biocontrol program, or Yampa River Leafy Spurge Program experts, depending on the need and situation.
General Integrated Management Principles for Leafy Spurge
Herbicides can be compatible with biological control. Fall herbicide application and early season grazing are the best choices if biocontrol is part of your program. Spurge is THE food source for biocontrol insects; spring herbicide application and/or late season grazing could adversely affect the insects you are trying to promote, and should be avoided, if possible.
Intensive tillage plus herbicide is generally incompatible with biological control.
Riparian areas that are not cut for hay, and which may not be suitable for herbicide use, can be good locations for biological control. Some biological control insects (flea beetles—Aphthona spp.) do not favor riparian habitat, but they can do well if large numbers (≈10,000) are released initially. This strategy is known as an “inundative release.”
Another biological control agent (leafy spurge stem-boring beetle—Oberea erythrocephala) appears well adapted to riparian environments, but little is known about its effectiveness. The YRLSP is working to learn more about this potentially useful insect because it seems to do very well in our area.
Human assisted revegetation can help increase competition with leafy spurge. Biocontrol insects damage the root systems of leafy spurge. Combining the two can push leafy spurge out of dominance over time.
Spot spraying patches of vigorous leafy spurge remaining in areas otherwise being managed with biocontrol can be effective at suppressing plants that may be resistant to biocontrol.