Genus - Enallagma

Taxonomic Hierarchy for Freshwater Invertebrate Collection


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6 results for "Enallagma"

Enallagma anna

Freshwater Invertebrate Collection

Enallagma boreale

Freshwater Invertebrate Collection

Common Nameboreal bluet SeasonalityAdults fly from late May to mid August in Alberta. Flight season extends in more temperate regions. IdentificationA large bluet, with adults ranging from 28-36 mm in total length and 17-22 mm in hindwing length. Males are blue (andromorphic), while females are polymorphic and range from light blue to yellow-green (Forbes 1991). Males have narrow humeral stripes and a wide median stripe on the thorax. Black abdominal banding is present in both sexes. In males, the first three black bands occurring on abdominal segments 3 to 5 are typically short and similar in length throughout, however, the black bands may increase in width towards the end of the abdomen in certain northern populations. These males may also possess a large black spot on abdominal segment 2 that touches the rear margin of the segment. Male abdominal segments 6, 7 and 10 are mostly black on the dorsal surface, while segments 8 and 9 are mostly blue. Males have a black subapical bar on the abdominal segment 2 (dorsal). In females, the abdomen is mostly black on the dorsal surface, with pale basal rings on segments 3 to 8. Abdominal segment 8 in females may have more blue or light brown than other segments, and at most may fill segment. When present within abdominal segment 8, the front margin of the black band typically tapers to a point on the dorsal surface. Female abdominal segments 9 and 10 are black. Male eyes are dorsally black and ventrally blue, while female eyes are dorsally dark brown and ventrally light brown. Postocular spots are large and may form dumbbell shape in both sexes. Boreal bluets are virtually indistinguishable from northern bluets (Enallagma annexum) except when viewed under magnification. Male boreal bluets and northern bluets differ in clasper morphology (McPeek 2011). Hagen’s bluets (Enallagma hageni) and marsh bluets (Enallagma ebrium) are similar in colouration, but both are notably smaller, may have smaller postocular spots, and have a larger spot on abdominal segment 2. Familiar bluets (Enallagma civile) are also similar in appearance, however the cerci are longer than paraprocts in familiar bluets, while the opposite is true for boreal bluets (Acorn 2004; Paulsen 2009).

Enallagma cyathigerum

Freshwater Invertebrate Collection

Enallagma ebrium

Freshwater Invertebrate Collection

Common Namemarsh bluet SeasonalityAdults fly from June to August in Alberta. Flight season extends in more temperate regions. IdentificationA smaller bluet, with adults ranging from 28-34 mm in total length and 16-21 mm in hindwing length. Males are predominantly blue (andromorphic), while females are polymorphic and range from light blue to yellow-green, the former being more common. Thoracic stripes are typical of most bluets in both sexes. Black abdominal banding is present in both sexes. In males, the first three black bands occurring on abdominal segments 3 to 5 increase in width towards the end of the abdomen. Male abdominal segments 6, 7 and 10 are mostly black on the dorsal surface, segments 8 to 9 are predominantly blue. Males have a large apical spot on the dorsal surface of abdominal segment 2. In females, the abdomen is mostly black due to broadening of abdominal bands on the dorsal surface. Male eyes are dorsally black and ventrally blue, while female eyes are dorsally brown and ventrally tan to pale green. Postocular spots are prominent and rarely separated, forming a dumbbell shape in both sexes. In certain populations, abdominal banding may be wider in marsh bluets than in Hagen’s bluets (Enallagma hageni); however, over much of its range, marsh bluets are virtually indistinguishable from Hagen’s bluets except when viewed under magnification. Male marsh bluets and Hagen’s bluets differ in morphology of cerci. The large size of the mesostigmal plates, or “shoulder pads”, of female marsh bluets differentiate them from all other female bluets save Hagen’s bluets; however, the mesostigmal plates of female marsh bluets lie flat towards their posterior end, while the mesostigmal plates of female Hagen’s bluets are raised above the thorax. Compared to marsh bluets, northern bluets (Enallagma annexum), boreal bluets (Enallagma boreale), and familiar bluets (Enallagma civile) may be similar in colouration, but all 3 are notably larger (Acorn 2004; Paulsen 2009).

Enallagma hageni

Freshwater Invertebrate Collection

Common NameHagen's bluet SeasonalityAdults fly from June to August in Alberta. Flight season extends in more temperate regions. IdentificationA smaller bluet, with adults ranging from 27-33 mm in total length and 15-21 mm in hindwing length. Males are predominantly blue (andromorphic), while females are polymorphic and may be range from light blue to yellow-green to light brown. Thoracic stripes are typical of most bluets in both sexes. Black abdominal banding is present in both sexes. In males, the black bands occurring on abdominal segments 3 to 5 increase in width towards the end of the abdomen on the dorsal surface. Male abdominal segments 6, 7 and 10 are mostly black on the dorsal surface, and segments 8 and 9 are predominantly blue. Males have a prominent apical spot on the dorsal surface of abdominal segment 2. In females, the abdomen is predominantly black due to widening of abdominal bands on the dorsal surface. Male eyes are dorsally black and ventrally blue, while female eyes are dorsally brown and ventrally tan or or pale green. Postocular spots are prominent in both sexes, forming a dumbbell shape. Over much of its range, Hagen’s bluets are virtually indistinguishable from marsh bluets (Enallagma ebrium) except when viewed under magnification; however, in certain populations, abdominal banding may be narrower in Hagen’s bluets than in marsh bluets. Male Hagen’s bluets and marsh bluets differ in morphology of cerci. The large size of the mesostigmal plates, or “shoulder pads”, of female marsh bluets differentiate them from all other female bluets except Hagen’s bluets; however, the mesostigmal plates of female Hagen’s bluets are raised above the thorax, while the mesostigmal plates of female marsh bluets lie flat towards their posterior end. Female Hagen’s bluets may also resemble female taiga bluets (Coenagrion resolutum), but may be differentiated by the presence of a spine on the ventral side of abdominal segment 8 in Hagen’s bluets. Northern bluets (Enallagma annexum), boreal bluets (Enallagma boreale), and familiar bluets (Enallagma civile) may be similar in colouration in both sexes, but all 3 are notably larger (Acorn 2004; Paulsen 2009).

Enallagma sp.

Freshwater Invertebrate Collection

Taxonomic Hierarchy for Freshwater Invertebrate Collection