Wisconsin Odonata Survey

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Enallagma ebrium  (Hagen, 1861)
Marsh Bluet


Coenagrionidae, Pond Damsel Family

The bluets form a group of about 17 similar species in Wisconsin in which the males usually share the characteristics of having blue and black stripes on the thorax, and blue and black markings on the abdomen. In-hand examinations are usually needed to identify them, although they can be grouped into subcategories based on the amount of black showing on the abdomen. Males are easily identified, under magnification, by the shape of their terminal appendages. Females are generally duller than males, and they are more difficult to identify, which is accomplished by subtle differences in the shape of the mesostigmal plates on the top of the thorax. Generally, males are bright blue while the females are green or yellow-green or blue. There are some species that are yellow-orange, a mix of various colors, or black with some blue.

Status-Global/State:

Global: G5     Wisconsin: S5    

Distinguishing Characteristics:

The male of this species is a blue-type bluet because of its predominantly blue abdomen. It is very similar to the Hagen's bluet in the field. The female is tan to green instead of blue. The body length of the marsh bluet varies from 1.0 to 1.3 inches.

Description of Habitat/Range:

Throughout northern United States and southern Canada, the marsh bluet is usually found in marshes, vegetated ponds, lakeshores, and quiet streams. This species generally are not found in acidic conditions. It is very common and widespread throughout Wisconsin.

Flight Season:

Early June to early September in Wisconsin.


Mar
Apr
May
Jun
Jul
Aug
Sep
Oct
Nov
5%
(20)
54%
(240)
34%
(150)
5%
(24)
2%
(10)
Shading illustrates monthly percentages of the total flight season records for the species. Each flight season record is a unique date/location/observer combination where one or more adult or an exuvia was recorded (excludes nymphs). The actual number of flight season records for each month is shown in parentheses.

Flight seasons begin earlier in the southern part of the state, often by a week or more. Also, flight charts may not be accurate for rare species because of few data available.
View user-submitted photos

(Click on photos to enlarge)
Photo of Male marsh bluet
Male marsh bluet. © Dan Jackson

Male marsh bluet
Photo of Male marsh bluet abdomen tip showing C-shaped cercus (upper part of clasper) in side view
Male marsh bluet abdomen tip showing C-shaped cercus (upper part of clasper) in side view. © Willson Gaul

Male marsh bluet abdomen tip showing C-shaped cercus (upper part of clasper) in side view
Photo of Marsh bluet pair
Marsh bluet pair. © Dan Jackson

Marsh bluet pair
Photo of Marsh bluet pair
Marsh bluet pair. © Dennis Paulson

Marsh bluet pair



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