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Enallagma aspersum
Azure Bluet

(Hagen, 1861)
Coenagrionidae, Pond Damsel Family
"Most Wanted" Species
photo of Male azure bluet
Male azure bluet — Dan Jackson
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: S2S3
Distinguishing Characteristics:
The male of this species is a black-type bluet because of its predominantly black abdomen. Varying from 1.1 to 1.3 inches in the length, the male and female are quite similar in appearance. The male is bluish with black stripes on the thorax, especially on the front. The abdomen is mostly black with some blue at the base and blue on the tip that extends forward to include the back half of segment 7. The female is similar, but the pale color is tan to dull blue. Her abdomen is black with pairs of pale marks on top of segments 7 and 8 and a black tip.
Description of Habitat/Range:
Ranging throughout eastern United States and extreme southeastern Canada, this species prefers vegetated and bog-bordered ponds or occasionally boggy swamps with no fish. It is known in Wisconsin from just a few widely scattered sites.
Flight Season:
In Wisconsin, adults have been documented from mid-May to early October.
(Click on photos to enlarge)
photo of Male azure bluet
Male azure bluet — Dan Jackson
photo of Male azure bluet
Male azure bluet — Dan Jackson
photo of Immature male azure bluet
Immature male azure bluet — Mike Reese
photo of Male azure bluet abdomen tip showing cercus (upper part of clasper) in side view
Male azure bluet abdomen tip showing cercus (upper part of clasper) in side view — Dan Jackson
photo of Female azure bluet
Female azure bluet — Dan Jackson
photo of Female azure bluet
Female azure bluet — Dan Jackson
photo of Azure bluet pair in wheel
Azure bluet pair in wheel — Dan Jackson
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