The large, often blue spotted, and indefatigable fliers found around the ponds, streams and lakes of the United States, go by the common name darners.
While the family breaks down into approximately forty different species, divided into thirteen genera, almost forty per cent of the species belong to the genus Aeshna, or Mosaic Darners. Many darner species also share some common physical characteristics. For convenience sake, think of darner identification in terms of two general rules of thumb.
First, body color serves as the distinguishing gender detail. Most males show blue patterns on otherwise darker colored thorax and abdomen. Females often, but not always, produce similar patterns in shades of yellow and green.
The absence or presence of thoracic stripes (top and side), along with their shape when present, serve as the second leading mosaic darner identification clue.
Tricanthagyna darners, a sutropical genera, make their presence known in North America with the Phantom Darner (Tricanthagyna trifida), pictured at the top of the page. Also called Three-spined Darners because of the three spines that protrude from the lower abdomen of females, Phantom Darners inhabit the forest areas of southern Georgia and Florida.
Adults emerge during the late summer and fall, and can be found flying through most of the warm spells of early Florida winter.
Typically adults hang out on trees and shrubs during the day, preferring to hunt for food as dusk approaches.
Male eye color changes over time from green to blue. Female eye color changes from green to brown over time.
Darners: genus Anax
North American hosts three Anax species, with an additional species sporadically migrating across the Mexican border to the Lower Rio Grande Valley of Texas.
Comet Darners (Anax longipes) call the lake and pond areas of Eastern North American home.
They migrate seasonally, and prefer coastal areas. Smaller populations are found inland.
The large size, green thorax and red abdomen of the male shown in the first picture, make it an easily identifiable native Anax species.
Females and immature adults also have a green thorax, although the thorax color dulls to a brownish shade.
Comet Darners inhabit a variety of eastern pond and lake areas, with a range extending from the Great Lakes in the north, to Florida in the south.
The Common Green Darner (Anax junius), the widest ranging of the Anax species, inhabits lakes and ponds from coast to coast. The video on the right column shows both the male and female. Large in size, Green Darner bodies grow up to three inches in length. A wing span extending to four inches in length insures they do not get overlooked by spectators within their territory.
In their southern ranges such as Texas and Florida, Common Green Darners can be found flying during the entire year. In their northern ranges, Common Green Darners prefer flying during the warm summer months.
The name Green Darner refers to the dragonfly’s eye and thorax color. Males, like the one pictured at the top of the page also have blue coloring along the abdomen. Females lack the blue coloring.
In 1997, the school children of Washington State voted the Common Green Darner the official state insect.
Mosaic Darners (Aeshna)
Most people think Mosaic Darner, genus Aeshna, when they think of darner dragonflies.
With the exception of areas in the Southeast, more than one dozen different mosaic darner species fly along North American waterways.
Generally the Mosaic Darners present themselves in a somewhat uniform manner, most having slim, blue, yellow or green patterned abdomens.
Thoracic stripe patterns among many mosaic darners slightly differ, providing one path for species identification.
The Variable Darner (Aeshna interrupta), top picture, initially get identified by the presence of thin stripes on both the front and side of the thorax. Often, but not always the stripes appear as dash marks rather than lines.
Based on that general description, the species in the first picture gets tentatively identified as a male Variable Darner.
Shadow Darners (Aeshna umbrosa) range across the northern half of North America from coast to coast.
Green stripes on the top and side of the thorax serve as their basic field ID clues.
The top thoracic stripes often split into two, with a small rectangle showing on the bottom of each stripe.
Usually Shadow Darners emerge during the late summer and fall. Because of their extended range, they can be found flying somewhere during the summer months.
Shadow darners inhabit marsh areas in and around forested areas. Males tend to perch more often than the typical, constantly flying Aeshna species.
With the exception of the Southeast, five Rhionaeschna species inhabit water areas throughout North America.
The California Darner (Aeshna californica), top picture, often can be found near western waterways during the spring.
The yellow spot at the top of the head, and the lack of top thoracic stripes, represent distinctive field identification marks.
Picture number two shows a yellow form, female California Darner.