Typically one generation is produced each year, but some populations are semivoltine, and larvae overwinter twice. Female tenerals take longer to develop since they have more mass to support in the developing ovaries. This stage lasts 4 days to several weeks, during which, tenerals fly and feeds constantly. They resume activity in mid-April, and molt and emerge from the water as a teneral, a sexually-immature adult. Larvae are able to withstand water temperatures as low as -4° C. As temperatures drop and winter approaches, the larvae overwinter. There are 5 or 6 larval instars, larvae reach the later instars by October. Typically, eggs laid in June hatch in July. Egg hatching time is water temperature dependent, taking as few as 11 days at 27.5° C to 61 days at 17.5° C. Adults typically emerge in the summer, when they mate and oviposit eggs in bodies of water, then die shortly after. Range wingspan 17 to 22 mm 0.67 to 0.87 inīoreal bluets are hemimetabolous.Average mass males: 0.032 g, females: 0.046 g oz.( Acorn, 2004 Anholt, et al., 1991 Forbes, 1991 Glotzhober and McShaffrey, 2002 Hecker, et al., 2002 Walker, 1944 Westfall Jr. Males of Enallagma species have unique terminal appendages, while females have unique mesostigmal plates, located behind and underneath the prothorax. Boreal bluets are especially similar to northern bluets ( Enallagma cyathigerum) though they are not found in the same area.

It can be difficult to identify individual Enallagma species, as many bluets must be distinguished microscopically. Their eyes are rather large, and their abdomen is covered in setae. Their gills are usually pale, and much longer than they are broad.

Final instar larvae can be distinguished by their prominent wing pads. The labium is long and hinged, so it rests beneath the head and covers the mouthparts at rest. Larvae have a large labium that can extend to catch prey. Larvae are aquatic, and have a long, thin body with gills on the posterior end. Sexually mature adults have brightly colored, firm bodies and clear wings. During the teneral stage, their wings have a rainbow sheen, and their body is soft and grey or brown in color. Their abdomen is mostly dark, with significant light areas on segments 8, 9 and 10. Their head and thorax are similar to males, though their femora have fewer black markings. One female morph shares a close resemblance to males in coloration and markings, while the other is tan, yellowish-green, or pale blue. They are also polymorphic, with two morphs. Females can be distinguished by the lack of pits on their pronotum. Their cerci are black and apically rounded in profile. There are 3 short dark bands, followed by 2 long dark bands on their abdomen. The dorsal side of their abdomen is bright blue, with pale blue or yellow on their lateral sides, and black markings and stripes.

Their legs are blue or tan with black stripes. Their pronotum is black, and their thorax is blue and fades to cream. Males have a blue face, while the back of their head is pale blue or yellowish. Their coloration is primarily blue and black. Due to their ovaries, females tend to weigh more, at about 46.0 mg, while males weigh about 32.6 mg. and May, 1996)Īdult boreal bluets are 28 to 36.6 mm in length, with a hind wingspan of 17 to 22 mm. ( Beirinckx, et al., 2006 Duffy and Liston, 1985 Glotzhober and McShaffrey, 2002 Paulson, 2011 Rivard, et al., 1975 Scultz, 2009 Westfall Jr. These bodies of water are located in woodlands, peatland bogs, marshes, and in the mountains. Adults are terrestrial, and typically can be found near the bodies of water from which they emerged. Boreal bluets are a freshwater species, though they can tolerate both saline and alkaline conditions. Their larvae are aquatic, and can be found in lentic habitats, typically slow streams, ponds, small lakes, and semi-permanent ponds. In the United States, they can be found from New England to California, and range as far south as Virginia in the east, and Arizona and New Mexico in the west. In Canada, they are widespread in the subarctic, from Nova Scotia to British Columbia, and north into the Yukon and the western mountains. They are common in northern North America, ranging from coast to coast in Canada and the United States. Boreal bluets ( Enallagma boreale) are a species of damselfly native to the Nearctic region.

Dragonfly larvae picture