Empowering Door County citizens and municipalities with the information, tools, and skills to tackle invasive species.
Empowering Door County citizens and municipalities with the information, tools, and skills to tackle invasive species.
June 30th Ridges staff, along with a volunteer, and the Door County Invasive Species Team headed out to map all populations of black swallow wort. Black swallow wort has been documented in Baileys Harbor since 2012. This year’s monitoring effort revealed several control successes in locations with historic populations, and illustrated the need for continued efforts, as new populations were identified along 42/57 through Baileys Harbor. DCIST has used these inventories to target control efforts.
Black swallow wort is not commonly found throughout the northern Wisconsin. These plants are so uncommon in northern Wisconsin that they are listed as prohibited meaning under the Wisconsin Invasive Species Law NR40 it is illegal to have these plants, and control is required. There is only one area in Door County with populations of black swallow wort, Baileys Harbor.
Monarchs are dependent on milkweeds as a nursery or host plant for their eggs and larvae. Without milkweed, the larva would not be able to develop into a butterfly. Monarchs use a variety of milkweeds, but there are several introduced milkweed plants called swallow-worts which are also eaten by monarchs. Swallow-worts have similar chemical properties to common milkweeds (Asclepias genus), which fool monarchs into laying eggs on them. Unfortunately swallow-wort species are not suitable food for monarch larvae and monarch caterpillars fail to develop into pupae when feeding on them.
DCIST, The Ridges, and other partners will continue to monitor for this plant. Early detection efforts for these small isolated populations are key for potential eradication. If you suspect you have this plant or know of a population please reach out to DCIST.
For more information on this story check out our July 2022 Newsletter: https://img1.wsimg.com/blobby/go/9d8bdf99-a469-4a63-b6aa-964398b2ffe0/downloads/July%202022%20DCIST%20Newsletter.pdf?ver=1659108078262
Vegetation hanging off of a Transducer photo taken by Samantha Koyen
