Length: typically 29-38 mm
On males, look for a broad black shoulder stripe, and an abdomen that has more blue than black. The black color is most extensive on abdominal segments six and seven. Segments eight and nine are entirely blue.
The eyespots are most often small and comma-shaped, or roundish, but unfortunately this is not true of every individual.
Immature males have a tan coloration in place of the blue.
The lighter color on females may be blue, tan, or greenish. On females, look for an abdomen that is mostly black on top. Eyespots and thoracic markings are the same in females as in the males.
The Familiar Bluet males can be seen flying very low over ponds, lakes, and slow-moving streams. As hunters, both males and females have the habit of plucking small insects off plants as they fly by. Favored perches include logs, the ground, and waterside plants; the species has a preference for perching horizontally, but can also be found perched diagonally.
While this species can be hard to distinguish from certain other bluets, fortunately most of the closest look-like species dont live in West Virginia.
The exception is Hagen's Bluet, Enallagma hageni. The Familiar Bluet and Hagens Bluet are so close in appearance, if they haven't been given an expert examination in the hand with a magnifying glass, they should be recorded as Enallagma civile/hageni.
One hint that may help make a probable identification of a Hagens or Familiar Bluet in West Virginia is habitat. Familiar Bluet is found across West Virginia, while Hagens has only been reported from the mountain counties at the eastern edge of the state. If a damselfly is found at a sphagnum bog in the eastern mountains, it is most likely Enallagma hageni, as that species has a preference for acidic water.
For site visitors outside West Virginia, note that elsewhere Hagens Bluet is not an exclusively mountain species, although the preference for acidic wetlands is true of Hagens Bluets everywhere.
Bick and Bick (1963) studied the behavior of Enallagma civile in the field in Oklahoma. They found that the newly emerged adults became sexually mature within 3-4 days. Although the Bicks observed 1,043 Familiar Bluets at their study pond, they never once saw an unaccompanied female. Any female that flew in from a nearby meadow was paired with a male before she got to the pond. Bick and Bick marked several hundred individuals, and were able to report that most males mated only once, and the same was true of most females.
Bick and Bick stated that males seemed to control most aspects of copulation, but females seemed in control of oviposition. One Familiar Bluet pair oviposited above the water for 158 minutes, then the female went underwater and oviposited there for another 15 minutes. One female ovipositing at the surface saw her guarding mate eaten by a Giant Water Bug, but continued to oviposit even after the bug finished eating the mate and made several attempts to seize her.
The Oklahoma Enallagma civile were preyed upon primarily by Giant Water Bugs and by Robber Flies. Other predators included Dolomedes fishing spiders, sunfish, and other Enallagma civile.
|Above: On top of the abdomen, the black coloration is most extensive on segments 6 and 7, while segments 8 and 9 are all-blue.|
|Above: Familiar Bluets in the wheel position for mating. The lighter color on females may be tan, greenish, or (as is the case here), blue.|