A member of the Somatochlora genus, otherwise known as the "striped emeralds." (1) Only one yellow thoracic side stripe is visible and it's pale and nearly circular (fades to obscurity over time). (2) The abdomen is dark and lacks distinctive pale spots. (3) Male claspers are pincer-shaped, and the female ovipositor is Y-type and only moderately long. Delicate Emerald (S. franklini) is similar but has longer abdomen that is widest at segment 9 (6 or 7 in Kennedy's). Incurvate Emerald has pale abdominal spots and different thoracic side stripes. This species is uncommonly found in the northern two-thirds of Wisconsin, often in early summer (June). I saw just one individual in 2008. 2009 update - Saw a few more individuals and added a couple photos of a female.