CDA hosts tour of Palisade Insectary
The Colorado Department of Agriculture recently hosted a tour along Fountain Creek near Pueblo to highlight a unique program that focuses on conservation through biological pest control. The Palisade Insectary is among only a handful of programs across the U.S. that provides farmers, ranchers and resource managers with dozens of species of beneficial insects and mites as tools for use in Integrated Pest Management programs.
"The Insectary is a symbol of Colorado's commitment to combating weeds and insect pests in an economical and environmentally sound way," said Commissioner of Agriculture John Salazar.
The Fountain Creek tour highlighted a major success for the Insectary. For the past seven years, the Insectary has been focused on collecting and releasing the tamarisk leaf beetle, Diorhabda carinulata. The little bug has had a tremendous effect by defoliating and eventually killing tamarisk on Colorado's waterways. During the tour, attendees were able to see firsthand how the tamarisk leaf beetle has helped a landowner manage a serious infestation of tamarisk.
Approximately 1,000,000 of these little weed eaters have been released on the Arkansas River and tributaries, including Fountain Creek. In just the past few years, the small yellow and black striped beetle has helped to defoliate tamarisk along at least 300 miles of river ways in western Colorado and left native vegetation, such as willows and cottonwoods, untouched and thriving. A similar success story is just beginning on the Arkansas River and its tributaries.
Colorado has about 92,000 acres of tamarisk infested lands and of that nearly 70,000 acres are found on the Arkansas River and tributaries. This infestation depletes water resources, alters stream channels, decreases wildlife habitat value, competes with native plants, decreases recreational opportunities and increases fire hazard.
The Arkansas River has more tamarisk than any other river in Colorado and major control efforts are underway with the cooperation of multiple agencies and landowners. The biocontrol program on the Arkansas includes the release of 1,000,000 tamarisk leaf beetles.
Tamarisk was introduced into the U.S. from Europe and Asia nearly 200 years ago and has since spread through the waterways of the west. At first it was considered useful since it was fast growing and required little attention but it has become a problem as it forms dense thickets and crowds out native vegetation. Tamarisk is highly flammable and can help fires spread rapidly through river ways. It also uses about 20 gallons of water per day for an average plant, which means tens of thousands of gallons used by dense thickets of tamarisk. The leaf beetle is a natural enemy of tamarisk and eats nothing else. It was collected from tamarisk in central Asia and brought over to the US to help in the fight against this noxious weed. Some of the first releases of this beetle in North America were made 11 years ago near Pueblo but it is just in the past two years that the insect has really started to take off in eastern Colorado.
The tamarisk beetles are one of about 20 species of beneficial insects and mites that the Insectary distributes for use against weeds and insect pests in Colorado. Some of these include the bindweed mite which slows the growth of and may eventually kill field bindweed. The knapweed flower weevil has controlled diffuse knapweed at many locations in Colorado and the leafy spurge flea beetles have controlled leafy spurge in many areas. The Insectary is also constantly working to provide the newest available beneficial insects for weed and pest control including beneficial insects for use against Russian knapweed and yellow toadflax.
For more information on the Palisade Insectary, visit www.colorado.gov/ag/csd and click on "Biological Pest Control Program."