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Somatochlora tenebrosa
Clamp-tipped Emerald

(Say, 1839)
Corduliidae, Emerald Family
"Most Wanted" Species
photo of Male clamp-tipped emerald
Male clamp-tipped emerald — Dan Jackson
The medium-sized, dark brown striped emeralds have some pale markings on the thorax and abdomen, black legs, clear wings and brilliant green eyes. The thorax has a metallic bronze-green sheen and the abdomen is dark metallic black-green. Most species are uncommonly seen, but this may be largely due to their secretive nature. When flying, most species look alike which is why in-hand identifications of their anatomical features are often needed.
Status-Global/State:
Global: G5 Wisconsin: S1S2
Distinguishing Characteristics:
The males are unique with a circular gap of appendages seen in side view at end of abdomen. The thorax has 2 yellow lateral stripes, which fade with age. The abdomen is all brown. The face varies in coloration from yellow to brown. Most of the females' wings become tinted brown with age. The body varies from 1.9 to 2.5 inches in length.
Description of Habitat/Range:
Found throughout eastern United States and southeast Canada, this species prefers shady forest waters, from trickles to streams, occasionally boggy and often partly dry. In Wisconsin, it is known from only a few sites in the central part of the state.
Flight Season:
In northern part of its range, the flight season is from late June to early September. The peak of the flight season, in Wisconsin, probably occurs in July.
(Click on photos to enlarge)
photo of Male clamp-tipped emerald
Male clamp-tipped emerald — Dan Jackson
photo of Male clamp-tipped emerald
Male clamp-tipped emerald — Dan Jackson
photo of Close-up of male clamp-tipped emerald thorax
Close-up of male clamp-tipped emerald thorax — Dan Jackson
photo of Side (top image) and top view of cercus for male clamp-tipped emerald
Side (top image) and top view of cercus for male clamp-tipped emerald — Dan Jackson
photo of Female clamp-tipped emerald
Female clamp-tipped emerald — Emily Hjalmarson
photo of Close-up of female clamp-tipped emerald thorax
Close-up of female clamp-tipped emerald thorax — Emily Hjalmarson
photo of Female clamp-tipped emerald abdomen tip
Female clamp-tipped emerald abdomen tip — Emily Hjalmarson
photo of Clamp-tipped emerald nymph
Clamp-tipped emerald nymph — Dan Jackson
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