Invasive Species

Invasive species threaten our native landscapes and waterways.  There are a variety of groups and individuals working to eliminate invasive species in Walworth County.

Wisconsin First Detector Network

The Network is a program developed by the University of Wisconsin to allow anyone to view information about terrestrial invasive species throughout the state of Wisconsin.  To access the network, use this link: Wisconsin First Detector Network


Lesser Celadine

Lesser Celadine was found in Walworth County in 2017 on the shores of Geneva Lake and in 2020 along Whitewater Lake.  Groups such as the Geneva Lake Conservancy, Geneva Lake Environmental Agency, Wisconsin DNR, and UW-Extension are working with landowners to try to eradicate this invader.LesserCelandine_elizabethjczarapata

  1. Lesser Celandine Flyer (PDF)
  2. Presentation on Wisconsin Forest Threat Lesser Celandine (PDF)

Starry Stonewort

Starry Stonewort was found in Geneva Lake in early 2019.  The Geneva Lake Environmental Agency is working diligently to lessen the impact of this aquatic invader.  The Agency's director, Ted Peters, presented information on this invasive species to the County's Land Conservation Committee in June of 2019.  


  1. What is Starry Stonewort (PDF)
  2. What is Starry Stonewort Power Point (PDF)
  3. Starry Stonewort Frequently Asked Questions (PDF)
  4. Starry Stonewort Research Factsheet (PDF)
  5. Starry Stonewort DNR Statement (PDF)