One of five species in Wisconsin of the genus Stylurus, the "hanging clubtails." Like other members of its genus, the Zebra Clubtail frequents clean, fast-flowing streams and rivers and is active mid-late summer, a bit later than most other clubtails. Note (1) the wide club in males, (2) the black abdomen with distinct yellow rings on segments 4 through 7, and (3) isolated, sausage-shaped, yellow top spots on the thorax. The ringed abdomen separates this from all other clubtails. I saw just a few individuals on the Marengo River in 2008.