NATURAL HISTORY

HINE'S EMERALD DRAGONFLY } Somatochlora hineana
FAMILY: Corduliidae

DESCRIPTION: Hine's emerald dragonflies have slender, metallic bodies with green, brown, or black coloring. Two distinct yellow lateral strips mark their thorax and fade into white as the dragonflies age. A brilliant, emerald-green color covers their enormous eyes, which possess almost 360-degree peripheral vision. These dragonflies have a wingspan of approximately three-and-a-half inches. Their wings are clear and may have an amber hue toward the base of the hind wings; wings may turn to a slightly opaque smoky color towards the end of life.

HABITAT: Hine's emerald dragonflies inhabit wetlands , spring-fed marshes, sedge meadows, and open areas in close proximity to forest boundaries. Cool, shallow, slow-moving waters provide important larval habitat, and the open areas adjacent to woodlands provide adult hunting and roosting opportunities. Hine's emerald dragonflies usually inhabit water only centimeters deep.

RANGE: Only a few sites scattered in Wisconsin, Illinois, Michigan, and Missouri are home to the Hine's emerald dragonfly today. Historically, this species was known to exist in Ohio and Indiana, and one specimen was even collected in Alabama. The dragonfly is believed to have already been lost from these states.

MIGRATION: This species does not migrate.

BREEDING: Soon after mating, which can last for up to an hour, impregnated females deposit their fertilized eggs by dipping their abdomens into the soft muck found in shallow water. Larvae molt many times as they grow their way toward adulthood and an aerial existence. Once they've reached a pre-adult stage, they stop feeding and crawl out of the water, where they gulp air to inflate and expand their bodies. After they break out of their larval skin and outstretch their wings, they wait as their bodies dry, then take flight.

LIFE CYCLE: Larvae live for up to five years, and adults live for at most seven weeks more. It is a short adulthood of feeding, sexual interaction, and egg deposition. When it emerges as an adult, a Hine's emerald dragonfly's eyes are brown, turning bright green within three days.

FEEDING: Larvae are voracious predators and feed day and night. They capture a wide range of invertebrates, larval amphibians, and small fish using a hinged lower lip, which can be flipped forward to trap prey on stiff bristles. Adult dragonflies spend much of their brief life feeding while in flight, capturing gnats, mosquitoes, and other small flying insects.

THREATS: The most significant threats to the Hine's emerald dragonfly include habitat destruction, urban sprawl, off-road vehicles, agricultural development, road and pipeline construction, logging, and groundwater contamination from pesticides and other contaminants.  

POPULATION TREND: Population densities of the Hine's emerald dragonfly are unknown throughout much of the species' range. What is certain is that only a few scattered breeding populations remain intact.

Photo © Paul Burton