Somatochlora provocans Calvert, 1903
Treetop Emerald
NatureServe Global Rank: G4
Virginia State Rank: S2
VA DGIF Tier: IV
Federal Legal Status: None
Virginia Legal Status: None
Description: The Treetop Emerald is about 2.0 inches long. It has a brownish-yellow face with a metallic black frons. The thorax is brown and metallic green with yellow stripes on the sides, the posterior of the two meets on the ventral side. The abdomen is black with a yellow streak on S2 and two yellow spots on the base of S3. The males have slender, pointed cerci that are angled inward from the dorsal view and slightly downward from the side view. The subgenital plate of the female is narrow, pointed and scoop-shaped.
Similar species: The Treetop Emerald is similar to a few other Emerald species that bear yellow stripes on the sides of the thorax. In Virginia, this would be the Clamp-tipped Emerald. They can be differentiated by the shape of the cerci and the subgenital plate. The Treetop Emerald's cerci are much straighter in the dorsal view, while those of the Clamp-tipped Emerald are rounder, bowing outward to each side to form a clamp-shape. In the females, the Treetop Emerald has a narrow, pointed, scoop-shaped subgenital plate while the Clamp-tipped Emerald is sharply pointed and projected at an almost right angle from the abdomen.
North American Range: There are two major populations, the first has a coastal distribution from southern New Jersey to North Carolina and barely into South Carolina. The second mainly extends from Kentucky south to Mississippi and Alabama.
VA Observations by Locality: Suffolk, City of | Caroline | Chesterfield | Essex | Sussex
Flight season and broods: In Virginia this species should be found active from June through September (July - August in North Carolina).
Aquatic Habitat: The Treetop Emerald prefers sand-bottomed forest streams and seeps, often in boggy conditions. It is more commonly found in the upper coastal plain than the lower coastal plain.
Behavior and Ecology: Treetop Emeralds are relatively high fliers, usually head height or above, well into the trees. They prefer open areas and roads through sandy pine forests and spend the heat of the day in the shade. Males patrol and hover often, about knee-height over seeps. Feeding occurs intermittently from dusk until dawn.
Population trend and potential threats: The Treetop Emerald may be negatively impacted by poor water quality and habitat degradation.
Management practices: Populations should be monitored and habitats preserved.
References: Bangma, J. 2003. The Dragonflies and Damselflies of New Jersey. http://njodes.com/Speciesaccts/species.asp . Accessed: 4/8/2013
Dunkle, Sydney W. 2000. Dragonflies Through Binoculars: A Field Guide to Dragonflies of North America. Oxford University Press, New York, NY. 266 pp.
LeGrand, H., E. Corey and T. Howard. The Dragonflies and Damselflies of North Carolina. http://www.dpr.ncparks.gov/odes/a/accounts.php. Accessed: 4/8/2013
Paulson, Dennis. 2011. Dragonflies and Damselflies of the East. Princeton University Press, Princeton, NJ. 530 pp.