2011 Purple Loosestrife Herbicide Control Report. Lisa Burns-AIS Coordinator Washburn County Land and Water Conservation Department Shell Lake, WI

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1 2011 Purple Loosestrife Herbicide Control Report Lisa Burns-AIS Coordinator Washburn County Land and Water Conservation Department Shell Lake, WI

2 Resource Problem to be addressed Purple loosestrife has been documented in Washburn County since the 1980 s. By far the largest infestations are in the Yellow River watershed and along the Namekagon River corridor. The National Park Service staff has worked hard over the years to manage the infestation along the Namekagon River, primarily through cutting and treating stems with herbicide. The Land and Water Conservation Department has focused beetle efforts on the Yellow River, both on the main channel and tributary streams. While bio-control efforts have been successful, there are still limitations to the number of beetles that can be raised each year and how much control they can provide. Cutting and treating purple loosestrife stems with herbicide has proven to accelerate the control process. Inventory of Treated Areas In July, with help from the WI DNR, loosestrife inventory along the Yellow River where treatment occurred in 2010 was completed. It was quite evident where plants had been treated, due to the brown foliage and dead stems left behind. In some areas, there were very few new plants growing, while other areas were already filling in with native species. As we approached some of the plants closer, there was evidence of Galerucella beetles and larvae feeding on the stems. Some plants were full of larvae alone, and were harboring major damage to the plants. This year s rice crop was very substantial along the river channel, making it difficult to paddle the further upstream we went. Fortunately, we continued seeing beetles and decided to leave those areas alone. Description of Work Due to a lack of time, no new landowners were contacted for treatment. The same cooperating landowners from 2010 were approached to treat purple loosestrife on their property, and permission was granted. An Aquatic Plant Management permit was received from the WI DNR for herbicide application and Glyphosate 4 Plus (Rodeo) was the herbicide used in the project. A blue dye was added to the herbicide to see what areas were cut. Working with DNR Water staff, a goal was to focus chemical treatment on the stretch of the river from Green Valley Road to the Hector Dam Road Bridge. DNR Wildlife staff used the same chemical treatment method on all of the shoreline on DNR property. After doing the inventory, and realizing there were a lot of beetles in the area, it was decided only a small portion of this stretch of the river needed to be treated (upstream of Hector Dam Rd). Each person was equipped with a garbage bag, pruner, rubber gloves and a bottle of herbicide. Canoes and kayaks were used to cut and treat stems along the edge of stands, while others walked directly on top of the loosestrife clumps. In the morning, we began treating large stands of purple loosestrife upland near tag alders. We cut the stems and bagged any with emerging flower heads. As we moved upstream and closer to the river, we began finding beetles and some larvae. At that point we only cut and bagged blooming flower heads, and treated the stem. As time went on, beetle eggs were being found and it was decided to completely stop treating the area, and let the

3 beetles and larvae forage. Bagged cut stems were hauled to an upland location to be dried and burned. Additional Areas of Work Yellow River landowners treated three parcels upstream near Green Valley Road. There were no flowering plants by the end of August and beetles were also found in these areas. A single floating bog on the Yellow River Flowage near Hwy 63 and Tony s Restaurant in Spooner was also treated and cut. A total of five large garbage bags were filled with cut stems and hauled to an upland location to be dried and burned. That patch had been there for years, and it was a big accomplishment to see it gone! Bio-Control Management It was very rewarding to see so many natural Galerucella beetles populating the Yellow River this year and making an impact of the loosestrife. This particular stretch of the river never had beetles released, only upstream and downstream. Considering none had been released there, they clearly found their way to the loosestrife stands on their own. Approximately 15,000 beetles were released this year between the treated stretch and Swan Bridge Road. It is the intent to continue beetle release efforts, along with chemical treatment to help manage and control stands of purple loosestrife.

4 Yellow River Purple Loosestrife Treatment Areas (Green Valley Road to Hector Dam Road)

5 Yellow River Flowage Purple Loosestrife Treatment Area (HWY 63 near Tony s Riverside Restaurant-Spooner, WI)

6 Pictures of Work Areas Yellow River: 2010 dead purple loosestrife stems from herbicide treatment.

7 Galerucella beetles feeding on purple loosestrife along the Yellow River that haven t been released there in the past.

8 Floating Bog of Purple Loosestrife near Tony s Restaurant in Spooner/Hwy 63 Cut and Treated on August 9, 2011

9 Partners in crime Lisa Burns and Kathy Bartilson cut and treated five large bags of purple loosestrife near Tony s Restaurant in Spooner.

10 Alex Smith cutting and treating purple loosestrife and Jane Malischke hauling it away from the Yellow River.