Minnesota Dragonfly

Williamson's Emerald

Somatochlora williamsoni

The Williamson's Emerald is a long dark Somatochlora, striped Emerald, with indistinct striping on the side of its thorax. They can be difficult to net because they often hunt woodland borders at around treetop height, sometimes joining with other species in feeding swarms


Field Marks
  • Average adult size is approximately from 2.0 to 2.3 inches
  • Dark metallic green face and frons with orange-yellow sides and metallic emerald eyes
  • Thorax is brown and metallic green with 2 indistinct, pale yellow stripes
  • Yellow spots on abdominal segment 2 with a ring separating segments 2 and 3
  • Dark, furry abdomen that is widest at the junction of segments 5 and 6
  • Pale rings separating segments 8 to 10
  • Small, pale, yellow side spots at the base of segments 5 to 7
  • Dark terminal appendages. Cerci slope down and then curl up at the ends. Cerci with small spike at the base, angled inward meeting at the tips

Click on photos above for a close-up view.

Field Marks
  • Female is colored similarly to the male
  • More distinct side spots on abdominal segments 4 to 8
  • Subgenital plate is longer than segment 9, perpendicular, and pointed
  • Cerci are longer than segments 9 and 10 combined

Click on photos above for a close-up view.

Natural History


Males patrol, with a combination of flying and hovering, a few feet above the water. Hunting usually takes place at woodland borders around treetop level, often as a part of a feeding swarm. I often see them hunting high above roads that cut through wooded or boggy habitats


Slow-moving, shaded streams, clear lakes, and bog ponds


Females lay eggs in wet, muddy soil above the water line. In between ovipositing they will dip their abdomen into the water, most likely to clean off any mud

Range Maps

Click on the icons above for this species' range maps

Click here for county and state checklists from Odonata Central.

Range maps and checklists courtesy of Odonata Central. Copyright © 2016 OdonataCentral. All Rights Reserved. Abbott, J.C. 2006-2018. OdonataCentral: An online resource for the distribution and identification of Odonata. Available at www.odonatacentral.org.