Excerpt: On July 21, 1969, two males and three females of the little-known species Somatochlora incurvata Walker were taken by the author at a tamarack bog in Clinton County, Pennsylvania. The bog, called "Tamarack Swamp" on the Pennsylvania State Geologic Survey map (15 minute series, topographic, Renovo West Quadrangle) is situated east and southeast of the small village of Tamarack. Three additional males were collected on July 26, 1969, and four females on August 9, 1969. Other individuals, mostly males, were seen on each occasion.
Shiffer, Clark N.
"Occurence and Habits of Somatochlora Incurvata, New for Pennsylvania (Odonata: Corduliinae),"
The Great Lakes Entomologist, vol 2
Available at: https://scholar.valpo.edu/tgle/vol2/iss2/6