A look at the integrated pest management of leafy spurge in Archuleta County


By Ethan Proud
PREVIEW Columnist

If you’ve been keeping up with these articles, then you noticed in this season’s management tip spotlights that I have mentioned that you have plenty of options for weed control, and herbicides are just one of them. In that vein, I’d like to showcase some integrated pest management going on in Archuleta County right now.

Within the Pagosa Lakes area, leafy spurge is running rampant, spreading south and north. This plant is a serious invader that can grow in riparian areas as well as in dry soils. It ejects its seeds 15 feet away from the mother plant while spreading from rhizomes and creating a dense monoculture that is often a single plant. Hand-pulling this plant will only yield new stems sprouting from the ground unless you get the entire root, which can be deeper than 15 feet below ground. A root fragment an inch or less in size can regrow an entire plant.

Leafy spurge in Archuleta County currently crosses a number of property types, making management a nightmare. The county actively treats county-owned property with herbicide and works with landowners who have current infestations of leafy spurge. To offset herbicide use, leafy spurge flea beetles have been deployed along the length of North Pagosa Boulevard with landowners who have granted the county permission. These beetles are host-specific to leafy spurge and cannot survive on another plant. If the spurge dies off, so do the beetles. 

The flea beetles are an example of biological controls which are monitored and regulated by the USDA APHIS program, which extensively tests potential biological control agents to ensure that they will not harm agricultural commodities or native plant populations. The leafy spurge flea beetles will reproduce and spread to other infestations of leafy spurge and are a sort of passive control. 

To ensure success, the Archuleta County Weed and Pest Department will keep releasing these agents in conjunction with participating landowners to help suppress the leafy spurge and rely on herbicides less. 

Roadsides are a vector of spread for leafy spurge as the seeds can be easily picked up by car and bike tires, or by those utilizing the bike path. Because of this, it is important to treat these populations with herbicide to prevent their further spread.

Archuleta County Weed and Pest is your local resource for managing noxious weed populations and controlling other pests.

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Visit us on the Web at https://archuleta.extension.colostate.edu/ or like us on Facebook and get more information: https://www.facebook.com/CSUARCHCTY.

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CPR and first aid certification classes are offered monthly by the CSU Extension office, generally on the second Monday and Wednesday of each month from 6 to 10 p.m. The cost for the classes is $80 for combined CPR/first aid and $55 for CPR, first aid or recertification. Call the Extension office at 246-5931 to register.