Common Green Darner

The common green darner is among the largest and most familiar dragonflies in North America, ranging from southern Canada through the United States into Central America. Its bright green thorax paired with a long, blue-striped abdomen (in males) makes it easy to pick out as it cruises over ponds and open fields.

Researchers have used the common green darner as a model species for studying insect migration, since it is one of the few dragonflies confirmed to complete a genuine multi-generational migratory cycle: individuals that fly south in autumn are not the same ones that return north the following spring, but rather their offspring.

• Large dragonfly, body length 7–8 cm with a wingspan up to about 11 cm
• Bright green thorax in both sexes
• Males have a blue abdomen with a dark dorsal stripe; females and immature individuals tend toward brown or reddish abdomens
• A rounded, target-like mark on top of the face (frons)
• Distinguished from other darners by combining a green thorax with this facial bullseye pattern

Common around ponds, lakes, marshes, and slow streams across nearly all of North America, from Canada to Central America, and occasionally observed migrating well offshore or over Pacific islands.

An agile, fast-flying predator that captures mosquitoes, midges, and other small flying insects in mid-air. Males patrol stretches of open water to court females and deter rivals. Populations in different parts of its range show either a migratory life history, flying long distances seasonally, or a resident life history, overwintering as an aquatic nymph in milder climates.

Eggs are inserted into aquatic plant stems. The predatory aquatic nymphs feed on other invertebrates and occasionally small fish or tadpoles, developing over months to more than a year depending on temperature. After a long series of molts, nymphs crawl out of the water to transform into winged adults; in migratory populations, this new generation makes the return flight north in spring.