Enallagma exsulans

Stream Bluet

Enallagma exsulans, Stream Bluet


Family: Coenagrionidae

Length: 29-37 mm


The Stream Bluet is one of many species of bluet damselfly found in West Virginia. While many bluet species prefer ponds and lakes, the Stream Bluetas its name impliesis most at home along moving waters. Look for it along small to medium-sized rivers. It is occasionally found at lakes too.

The Stream Bluet is one of those bluet species that are predominantly black toward the middle, with substantial blue at each end. One important identification characteristic is that all of abdominal segment nine is blue on topand this is true only of segment nine. (Segment nine is the penultimate segment of a dragonfly's abdomen.)

Stream Bluet, Enallagma exsulans face

In many species of dragonflies the males have a blue tip to the abdomen. The Stream Bluet is one of those less common cases where the female, too, has a blue abdominal tip. In the case of females, the top of segment ten is all blue, while part of the top of segment nine is blue. The photos below will make clearer this coloration pattern.

Summertime is the time to look for this species. Few species of damselfly or dragonfly have been collected more often in West Virginia than the Stream Bluet. It probably occurs in all fifty-five counties.

Stream Bluet, Enallagma exsulans

The blue eyespots are not overly large on the Stream Bluet.

Note how abdominal segment nine is the only one that is all-blue on top.


Stream Bluet mating, Enallagma exsulans 
 The male (above) and female have just assumed the wheel position for mating.


Stream Bluet female, Enallagma exsulans 

 On this female Stream Bluet, note the pattern of blue on the tip of the abdomen.


Stream Bluet female, Enallagma exsulans 
Coloration of the top of the thorax of the female Stream Bluet can be beautiful. On this individual there is black, green, and yellow.

Insects of West Virginia