Biological Control for Biological Control Basics: Weed Management Advantages Disadvantages Status of Biological Control Agents on Target specific Initial high costs Weeds Most successful weed Continuous action Long time until  Knapweed Agents – Seedhead feeders management plans use results seen Long-term cost Uncertain results are everywhere in the county and are a number of methods: herbicides, effectiveness becoming more widespread. Work in mechanical, cultural, and when Gradual in effect, Uncertain ‘non- Canada shows the best control if appropriate biological control. Use of environmentally target’ effects in the seedhead feeders and root feeders are multiple methods at the same time is friendly environment combined. called Integrated Pest Management – or Can move on their Can not be  Toadflaxes – Flower feeding beetles are IPM. own (even into difficult removed likely already in your yellow toadflax. A terrain) stem-boring weevil that attacks both Biological control of weeds is the use plants is showing promise in Canada. of one organism to control another. Things to Know:  Purple Loosestife – Galerucella beetles Classical biological control is the  Efficiency of agents cannot be are the most abundant and dramatic agent. Beetles may reduce flowering by introduction of control agents – usually guaranteed.  Will not work every time in every situation. eating all the leaves. insects – into a region that is not part of  Leafy spurge –Beetles (Apthona species) their natural range, to permanently  Will not “eradicate” the weed (no complete kill) that eat the leaves and seed have been reduce the populations of selected weeds the most visible and effective so far. usually also introduced into the region.  May not provide the desired level of control  Canada thistle – Best bets are gall flies REDUCE, not GET RID OF! (Urophora cardui) and seed head weevils  Some times it might take years before you (Larinus planus). see biological control impact.  St. Johnswort – Chrysolina beetles are How Biological Control Works most commonly encountered and most Some Questions to Ask Yourself: effective. Agrilus beetle larvae feed on the  Biocontrol agents or bio agents may  Do I want eradication? – biological root, you must pull up plants to see control weeds by destroying seeds, control is not a good fit with this goal. leaves, root, or stems; by weakening damage.  Do I want to reduce weed abundance? – or stressing the weed; and/or by depending on weed and control agent – For more information: limiting the weeds ability to reproduce. maybe.  Bioagent feeding may also help  How soon do I need results? Yesterday?  Idaho Program: http://www.agri.idaho.gov 1 to 2 seasons? within 5 years? weaken weeds through damage scars.  Federal Programs: Federal Interagency Biological controls take years to show  Once established and feeding in your Committee for the Management of results. weed infestations, bioagents will Noxious and Exotic Weeds  Do I have lots of money, time, or people? continue to attack your weeds, month http://www.fs.fed.us/ficmnew/index.shtml Other management tools such as  Local Programs: Contact your State after month, year after year. herbicides, mechanical, or cultural Department of Agriculture, County control may help you achieve your goals Noxious Weed Department, Local sooner. Cooperative Weed Management Area  Do I have little time or money? If you (CWMA) or Extension Agent. can’t manage your weeds in any other way, biological control may be better than nothing. Using Livestock Benefits of grazing for weed control: for Weed  Low impact to environment  Convert weeds into saleable product Management  Can be used with other control methods Biological  More long lasting control Prescription grazing –  Good for rough terrain is carefully controlled grazing to meet land management objectives. It can reduce weeds Control of Website with grazing guidelines for weed in crop systems, control weeds in tree crops, control: remove weeds in sensitive areas, and control weeds on range lands. http://www.webpages.uidaho.edu/rx- Weeds

grazing/ Keys to prescription grazing:

 Timing of grazing – when weeds are most Biological Control may be an susceptible and taste best to the animal, Option for your Weed Problem when desired species are least tasty or IF….. least susceptible to damage, in Idaho, generally early spring.  You don’t expect the weed to be totally  Frequency of grazing – Depends on the destroyed, weed species; life span, reproduction, longevity of seeds in soil, and how does it  You don’t need instant gratification, react to grazing.  You are willing to check release sites  Stocking rate – How many animals do you for establishment and impact need on how much acreage? It depends  You are willing to give the agents the on the density of the weed infestation, the time they need to work (2-5+ years) palatability of the weed, and your specific before resorting to other weed goals. management options (spray,  Pick the right animal for the job – Pick mechanical, cultural). the correct species and breed for your

weed. It is a myth that any old goat (or sheep, or cow) will do. Noxious Weed Control

Costs of grazing for weed control:  Difficult to find supplier Kootenai County does not 10905 N RAMSEY ROAD discriminate against individuals or Hayden, ID  High operating expense groups on the basis of disability in the  Can reduce native plant populations admission or access to, or treatment 208-446-1290  Can increase spread of weed seed in, its public meetings, programs, or TTY 208-446-2145  May be incompatible with wildlife activities. Requests for assistance or [email protected] accommodations can be arranged by www.kcweeds.com contacting the Noxious Weed Control Department at (208) 446-1290 or County Administration Office TTY (208)446-2145 with 3 days advance notice.