St. Croix Snaketail (Ophiogomphus susbehcha) has an interesting history in Maryland. For a number of years, unidentified early-emerging Ophiogomphus were known from the Potomac and one or two other rivers in the region. A male specimen was collected from Frederick Co. by Richard Orr in 2002, and a fair number of exuviae were collected over the next decade or so. As more adult specimens were collected, and the known range was expanded to include the James River in Virginia, the snaketail compared to other Ophiogomphus, and was found to be extremely close to Ophiogomphus susbehcha of Wisconsin. The eastern individuals differed primarily in smaller size than that of the types. The eastern snaketails ('Chesapeake Snaketail') are now considered by several experts to be conspecific with susbehcha, but perhaps warranting a subspecific designation (Richard Orr's account of the discovery and identification progress at http://www.marylandinsects.com/PotomacSnaketail.html). This species in Maryland is known only from the Potomac River in Frederick Co., and is consequently ranked as S1 (highly state rare).
Ophiogomphus susbehcha, the St. Croix snaketail, is a species of clubtail in the family of dragonflies known as Gomphidae.[1][2][3][4] It is found in North America.[1]
The IUCN conservation status of Ophiogomphus susbehcha is "LC", least concern, with no immediate threat to the species' survival. The population is stable.[5][6]
Kalkman, V. J. (2013). Studies on phylogeny and biogeography of damselflies (Odonata) with emphasis on the Argiolestidae (PhD). Leiden University. hdl:1887/22953.