Dalmatian toadflax invasion after the High Park fire of 2012

Colorado’s Biological Control Program is part of the Conservation Services Division within the Colorado Department of Agriculture. Biological control, or biocontrol, is the use of living natural enemies to control pests, which can include insect pests or noxious weeds.

The Palisade Insectary, located in Palisade in the midst of peach orchards, is headquarters to the program, which got started back in 1945 when the peach farmers of the Grand Valley were confronted with the Oriental fruit moth or OFM, which threatened the local peach industry. A biocontrol agent was available and the Palisade Insectary got its start by rearing millions of them, small parasitic wasps known as Mac, to attack OFM larvae, killing them before they emerge as adult moths. The project was a success, which opened the door for further use of biocontrols to manage the state’s weeds and insect pests.

The insectary located in Palisade, Colo. and operated by the Colorado Department of Agriculture

The Palisade Insectary breaks our strategic biological control plan into implementation, monitoring and education, and we use these three components with all of our programs, new and old. The Insectary staff implements biocontrols by learning how to best release and establish agents and releasing them throughout the state. We rear a number of biological control organisms within our 14,000-square-foot building, two greenhouses and an acre of irrigated garden space. Once established in the field we can collect and redistribute some agents far more efficiently from naturally occurring populations than from laboratory-reared cultures. We monitor agent and pest populations in the field, allowing a measure of success and directed releases of biocontrol agents where most needed. We educate end users regarding availability and expectations for biological control.

Fighting against Noxious Weeds

Field bindweed heavily infested with mites in later stages just before plant death

We distribute agents for use against some of Colorado’s most difficult weeds including yellow toadflax, Dalmatian toadflax, diffuse knapweed, spotted knapweed, Russian knapweed, leafy spurge, musk thistle, Canada thistle, puncturevine, tamarisk, and field bindweed. We also distribute agents for use against insect pests including OFM, emerald ash borer and Japanese beetle. The Biological Control Program is dynamic in that we take on new projects as biocontrol agents become available. As we take on new projects we also scale back on projects where we know the agents have been widely distributed in Colorado and are now self-sustaining in the field.

Scientific Specialists

All of our full-time staff members have bachelor’s degrees in biology or related fields. Some also hold graduate degrees in fields relevant to biological control. Each biocontrol target has a separate program with a program manager who specializes in the target.

Canada thistle with early summer form of the rust fungus, Puccinia punctiformis
  • Nina Louden is program manager for field bindweed biocontrol, musk thistle biocontrol and tamarisk biocontrol.
  • Karen Rosen is program manager for Canada thistle and has worked statewide on controlling Canada thistle since 2013.
  • Mike Racette manages the OFM project as well as puncturevine and the toadflaxes.
  • Sonya Daly manages the Russian knapweed biocontrol program and is a mapmaker for the Insectary.
  • Kristi Gladem directs a new program to rear agents for use against yellow starthistle. She also works on data management and has recently helped upgrade the Request-a-Bug program, which allows the public to receive biological control agents.
  • John Kaltenbach is head of our operations on the Front Range and eastern plains and works out of our main office in Broomfield. John is program manager for leafy spurge, diffuse and spotted knapweeds, emerald ash borer and Japanese beetle. 
  • Teresa Rodriquez keeps the office running, assists on the OFM project, produces educational material and researches the biology of the northern tamarisk beetle.  

Safe, Economical Biocontrols

Colorado’s Biological Control Program serves agricultural producers across the state by providing safe and economical biological control options, particularly for rangeland weeds. The Insectary works with county and municipal weed and pest managers through a subscribers program that enables weed and pest managers to receive multiple releases of their most needed biocontrol agents, as well as providing on-site evaluations of weed infestations. We also work with the Bureau of Land Management, the Department of Defense, the U.S. Forest Service, the National Park Service, and Colorado Parks and Wildlife, as well as others. We serve the public through a program called Request-A-Bug.

For most insect and mite pests commonly found in greenhouse settings, biocontrol agents are available through private suppliers so we don’t carry agents for control of aphids, scale insects, spider mites, and other common greenhouse pests. We do carry field bindweed mites, which are otherwise not readily available.

Bindweed Mites & Rust Fungus for Canada Thistle

Dalmation toadflax weevils in a cardboard container for release

Mites can be ordered through the Request-A-Bug program. After we receive an order, we collect and ship bindweed with a characteristic pathology including gnarled structures barely recognizable as bindweed leaves, which house the mites. They arrive in a cooled, shipping box with infested bindweed leaves. These are applied to healthy bindweed and like all biocontrols, it takes time for the mites to kill the host plant but with the constant stress of shortened vines and curled leaves the mites eventually kill many of the plants that they infest. 

Another program of interest to the nursery industry is Canada thistle (CT) biocontrol. We have a host-specific rust fungus that lives within the extensive root systems of CT patches and weakens the plants over several seasons. To infect a CT patch, we provide a finely ground powder containing infective spores of the fungus.  The spores are applied to rosettes of CT in the fall when they are able to germinate and travel down into the root system. 

The Request-A-Bug program provides agents to the public for a small fee. We ship releases, usually overnight, and provide instructions along with the agents. It is best to get on the request list as soon as you can. In some cases we can get requested agents in the mail within two to three weeks, but usually it takes longer. We ship agents during the season when they are best applied to the problem weed.  Please check our website for further information on the timing of availability of agents of interest.

The Palisade Insectary is unique in that it provides a direct link between development and implementation of biological controls and the end users that need them. Colorado is the only western state to support a facility such as ours, which enables us to obtain federal funding for biocontrol research and development. This lets us stay at the forefront, making biocontrols available to end users in Colorado. To support us please check into possible ways you can use our biocontrol agents, and pass the word around that Colorado has yet another thing to be proud of in the form of biological control and the Insectary.

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