Overview
Hine’s Emerald Dragonfly (Somatochlora hineana) is one of North America’s rarest and most endangered odonates. Famous for its dazzling, gem-like emerald-green compound eyes and metallic bronze thorax, this magnificent wetland insect survives only in rare calcareous fens where cool, alkaline groundwater seeps through porous dolomite limestone bedrock.
Biology and Physical Characteristics
Adult Hine’s emeralds possess a slender, dark metallic-bronze to emerald-green body with two distinct creamy-yellow diagonal stripes running down each side of the thorax. Their most striking feature is a pair of massive, contiguous compound eyes that glow with an electrifying jade-to-emerald green iridescence in mature adults. Their transparent wings feature clear amber bases and dark pterostigmata engineered for rapid acrobatic flight maneuvers.
Behavior and Ecology
Adult dragonflies cruise along woodland edges and sedge meadows during sunny summer days, hawking swarms of gnats and mosquitoes mid-air. Breeding occurs over shallow marsh rivulets, where females plunge the tip of their abdomen into organic mud to deposit eggs. The aquatic nymphs are uniquely adapted to survive periodic summer droughts by seeking refuge inside the subterranean water-filled burrows excavated by burrowing devil crayfish (Cambarus diogenes).
Conservation and Human Impact
Federally listed under the Endangered Species Act and evaluated as Endangered by the IUCN, Somatochlora hineana has lost over 95 percent of its historical fen habitats to urban sprawl, quarrying, wetland drainage, and highway construction across the Chicago and Des Plaines River corridors. Conservation agencies and land trusts manage delicate hydrological aquifers, eradicate invasive reed canary grass, and protect crayfish-supported breeding seeps.
Interesting Factoid
When the shallow fen seeps dry up during hot midsummer weeks, Hine’s emerald dragonfly nymphs crawl into the cool, subterranean muddy burrows dug by crayfish, coexisting underground until autumn rains return!
Last updated: October 2026