Pond Damselflies
Family Coenagrionidae
Genus Enallagma
Northern Bluet (Enallagma annexum)



"Blue-type" Bluet – the male's abdomens are predominantly blue when viewed from above. This damselfly has large eyespots and tapering, relatively narrow shoulder stripes. Similar species – Boreal Bluet (Enallagma boreale) and Vernal Bluet (Enallagma vernale) – see below.


Flight season: mid-May to early September.

Population: common, generally to the east of town along the trans-Canada Trail near water filled ditches and other small bodies of still water. This damselfly appears to have a bimodal flight season – large numbers appear in early spring, few or none are seen throughout the summer months, and adults again appear in very late summer.

Length: about 35 mm, fairly robust and distinctly larger than other species apt to be flying at this season such as Boreal and Marsh Bluets. The only certain means of separating this species from the Boreal and and Vernal Bluets (particularly the females) is by study of the male's cerci or the female's mesostigmal plates. Several damselflies were examined with a 20× loupe to establish they were indeed Northern Bluets.


East of Tweed, Ontario, along the trans-Canada Trail: shady forested area with clearings, both natural and created by the trail, supporting grasses and wildflowers.
Male Northern Bluet (Enallagma annexum), terminalia – the cerci have a sharply upturned hook at their tips; compare to the rounded downturned cerci of the male Boreal Bluet. However, it should be noted that there is insufficient information in this image to distinguish the damselfly from a Vernal Bluet (May 27, 2014).


East of Tweed, Ontario, near the intersection of Lajoie Rd. and the trans-Canada Trail: a shady wooded area, with clearings both natural and created by the trail supporting grasses and wildflowers, the lagoon lies nearby to the northwest.
Images of a male Northern Bluet (Enallagma annexum) and its terminalia (August 05, 2014).


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An immature female Northern Bluet (Enallagma annexum) – the paired blue spots on S8 are fused in most individuals (August 05, 2014).


East of Tweed, Ontario, near the intersection of Alexander Street and the trans-Canada Trail: disturbed field supporting tall grasses and wildflowers, bordered by shrubs and trees with a sand and rock-bottomed creek to the east.
Immature female Northern Bluet (Enallagma annexum)
August 04, 2014


Vernal Bluet (Enallagma vernale)


Flight season: mid-May to early July.

Population: uncommon.

Length: about 30 mm.

The males of this damselfly are separated from Northern Bluets by the tooth-like projection on the cerci, visible when viewed from above. Two males were captured in Tweed, Ontario, the Moira River near the walking bridge and dam, one on May 20, 2016 and the other on May 25, 2016. The cerci were examined at 60× under good lighting.

No images currently available, the details are beyond the limits of the camera's macro.