Root Weevils Released at Anoka Nature Preserve for Biocontrol

At the beginning of August, we released 100 root boring weevils to help control a population of spotted knapweed at the Anoka Nature Preserve (ANP), in the City of Anoka. Spotted knapweed is an invasive plant native to Eurasia that is spreading across Minnesota. It releases a toxin that threatens nearby plants, giving it the tools to outcompete and dominate, and thereby decreasing biodiversity. 

Root boring weevils are a method of biocontrol that target knapweed without affecting surrounding native plants. As larvae, root weevils burrow into the roots of spotted knapweed and feed on them throughout winter and spring, leaving the plants dead or weakened. The weevils we released at ANP were adults who will lay their eggs at the base of the plants through early fall and hopefully begin to weaken the population of spotted knapweed within the preserve.

ANP was a promising candidate for root weevils biocontrol because the site has a large, dense population of spotted knapweed, and the weevils will not be disturbed by mowing or other land management activities. It can take several years to see the effects of the weevils, and the site will be monitored to see if they have been established. The weevils were provided by Monika Chandler from the MN Department of Agriculture, who delivered them in a sealed paper cup where they were kept refrigerated or in a portable cooler until the time of their release later in the afternoon. 

Article and photos provided by Sally Herman, Seasonal Technician with ACD  

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Project Showcase

Summer, 2023 at a riverbank project, installed in 2021, in Mississippi River Community Park is thriving in 2023. The project included tree clearing, regrading, riprap, seeding, and planting of a variety of native plant species.
A gravel bed was installed in May, 2023 at the ACD Office. Gravel beds are designed to store bare-root trees and shrubs while enhancing root development.
A riverbank stabilization project on the Rum River was installed June, 2023 that implemented brush wattles, cedar tree revetment, native seed and hydro mulch with an additional 1,000 native plants being planted in Fall, 2023.
In Spring, 2023 ACD staff recorded 34 native plant species growing at a lakeshore restoration on Fawn Lake in North East Anoka County. This restoration was installed Spring, 2022.
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Check out a recap of ACD's 2023 Tree Sale!

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Welcome Brian Clark!

Brian Clark joined the Anoka Conservation District in March 2023 as a Natural Resource Technician. He holds a Bachelor's degree in Civil Engineering from North Dakota State University in Fargo, North Dakota. He is also a licensed Professional Engineer in the State of Minnesota.

Brian was born and raised in Blaine, Minnesota. After graduating from college, he had the opportunity to work for the federal government as a structural engineer at a public shipyard in Bremerton, Washington. After four years, he returned back to Minnesota and joined the Anoka Conservation District team to develop a career focused on natural resource management and environmental remediation.



Brian will be providing technical assistance with water monitoring, natural resource inventories, landowner assistance, project installation and inspections, invasive species management, and product processing and distribution. He has aspiring goals to use his Civil Engineering background and his licensure as a Professional Engineer to provide a unique benefit to the Anoka Conservation District.

Brian has a creative soul and enjoys playing music, writing, and videography. He enjoys the Minnesotan outdoors – from the blistering cold winters to the hot and humid summers – and you can often find him walking at the local parks and trails within Anoka County. He has had the opportunity to travel around the world for work and has spent up to several months at a time in locations like Japan, Guam, Hawaii, California, and sometimes on an aircraft carrier in the middle of the Pacific Ocean. 

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Water Quality Improvement Project Highlights - 2022

- Carp are an invasive species that degrade water quality. ACD coordinated the removal of 14,518 carp from Martin and Typo Lakes to improve habitat and water quality. Project partners included the Sunrise River WMO, the Martin Lakers Association, and Linwood Township.

- Twelve rain gardens were installed to improve water quality by reducing volume and pollutants in stormwater runoff before it reaches priority waterbodies. Project partners included landowners, the Cities of Anoka, Fridley, and Ramsey, the Lower Rum River WMO, and the Rice Creek Watershed District.


- 14 lakeshore stabilization projects were installed throughout Anoka County. The projects reduce shoreline erosion and provide wildlife habitat. Partners included landowners, the Sunrise River WMO, the Rice Creek Watershed District, and the Upper Rum River WMO.

- Eleven streambank stabilization projects were completed on the Rum and Mississippi Rivers. These sites have had significant and accelerating erosion issues due to sustained high water and increased recreation on the rivers.

- Over 5,000 linear feet of Cedar Tree Revetments were installed along the Rum River. These projects were in partnership with the Anoka County Parks Department and Conservation Corps, MN. 

- ACD partnered with landowners to provide funding assistance for the replacement of 4 failing septic systems and the sealing of 20 wells  which present a threat to surface and groundwater resources.

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