Frequently Asked Questions About the Palisade Insectary

Mission Statement How do I get ? You can call the Colorado Department of We are striving to develop new, effective Agriculture Insectary in Palisade at (970) ways to control non-native species of plants 464-7916 or toll free at (866) 324-2963 and and that have invaded Colorado. get on the request list. We are doing this through the use of biological controls which are natural, non- When are the insects available? toxic, and environmentally friendly. We collect and distribute adult beetles in June and July. The Leafy Spurge Program In Palisade How long will it take for them to control my leafy spurge? The Insectary has been working on leafy Biological Control You can usually see some damage at the spurge bio-control since 1988. Root feeding point of release the following year, but it beetles are readily available for release of typically takes three to ten years to get in early summer. Three other species widespread control. have been released and populations are growing with the potential for future Leafy Spurge What else do the beetles feed on? distribution. All of the leafy spurge feeding The beetles will feed on leafy spurge and insects are maintained in field colonies. cypress spurge. They were held in Additional research is underway to explore quarantine and tested to ensure they would the potential use of soilborne plant not feed on other plants before they were pathogens as biocontrol agents. imported and released in North America

What makes the best release site? A warm dry location with moderate leafy spurge growth is best. For example; a south facing slope out of the trees. The beetles will establish in less than optimal sites, but it usually takes longer.

How do I release them? For more information on the Leafy Spurge After you select a site, simply open the biocontrol program at the Insectary, please bag/container and release all the beetles in write or call: one area. They will disperse themselves. Dan Nees, Ag Program Specialist Division of Conservation Services 750 37.8 Road Division Palisade, CO 81526 (970) 464-7916 Toll free (866) 324-2963 [email protected] Palisade Insectary

What is Leafy Spurge? Release Success Biological Control of Leafy Spurge Leafy spurge, , is thought to have originated in Asia and was discovered To help control leafy spurge, the Colorado The leafy spurge project has had much in Massachusetts in Department of Agriculture success in its efforts to control the leafy spurge 1827. Currently, leafy initiated a biological throughout Colorado. The Aphthona beetles spurge is found in control program using a are great examples of how biological control every northern state number of plant feeding can work. To date there have been thousands with severe infestations insects. The most of successful release sites and over a million in Colorado where it is A species of flea effective of these are five acres reclaimed. Research on this system is a prohibited, perennial, species of flea beetles; , ongoing, not only to ensure continued success, Leafy spurge noxious weed. The , , but to increase the success rate and reclaim white, milky latex that , and . more of Colorado’s agricultural and is present in all parts of the plant causes As larvae, the flea beetles feed on the roots; recreational areas. severe irritation of the mouth and digestive as adults they feed on the leaves. Heavy tract in cattle. Because of this, cattle avoid larval feeding damage is sufficient to kill the grazing where leafy spurge is present. plant.

Leafy spurge can reproduce from seeds or vegetatively from buds on its extensive root Aphthona Life Cycle system. The seeds are contained in capsules that explode when dry - projecting Egg laying adult them as far as fifteen feet from the plant. Aphthona beetles These seeds can remain viable for up to are collected from seven years in the soil. infested plants in June and July A 1990 study conducted by North Dakota and released in State University estimated the direct annual uninfested A large collection of beetles Leafy spurge site in Rio Blanco County before financial impact in North Dakota, South patches of leafy beetle release (1989) Dakota, Montana, and Wyoming to be $40.5 spurge. The adults lay million. The most effective herbicides for their eggs on or near controlling leafy spurge are very expensive the crown of the plant. and require repeated application to After the eggs hatch effectively control leafy spurge. In addition, the larvae move into these the soil to feed on the herbicides root hairs and small have restricted roots. The larvae use due to the overwinter in the soil. detrimental The following spring effects they the larvae finish have on the feeding then migrate environment. A leafy spurge covered to the crown of the with beetles Hillside infested with leafy spurge plants to pupate and Leafy spurge site in Rio Blanco County after finally emerge as adults in June and July. beetle release (1999)