Easily identified Aeshna

In contrast to the difficult to distinguish females of the Lance-tipped Darner and Black-tipped Darner, the following two dragonflies are distinctive and can often be identified in flight if seen at close range. The females of both species are colored and patterned pretty much like the the males.

Shadow Darner (Aeshna umbrosa), male – photographed in early September

Habitat – Tweed, Ontario: a marsh west of town, bordering the Eastern Ontario Trail (44.46889°, -77.31528°). Typical local wetland with rushes, Cattails, Arrowheads and other emergent vegetation, the predominant shrubs are Speckled Alders and various species of Willow
Behavior – prefers to fly over small open areas of water among the alders and willows

– the narrow yellowish-green thoracic stripes are recurved at the top (underneath the wings), resembling walking canes
– relatively small greenish abdominal spots, giving the dragonfly a darker aspect than other local Aeshna spp
– the spatulate cerci appear similar to those of the Lance-tipped Darner when viewed laterally, but are wider and look very different in dorsal view
– no cross-stripe on the face, or a very thin brown line at most

A green form female Shadow Darner encountered in late September.

Mottled Darner (Aeshna clepsydra), male – photographed in early September

Habitat – Tweed, Ontario: Stoco Lake, east of the boat pier (44.474563°, -77.306227°). Sand and mud bottom, relatively shallow stagnant water, emergent plants such as rushes, White Water Lilies, Wapato and Pickerelweed
Behavior – forages low amidst the rushes and other emergent vegetation along the lake shoreline

– the lateral sides of the thorax are mottled in yellow, green and blue
– relatively large light blue abdominal spots, giving the dragonfly a much paler aspect than other local Aeshna spp
– the cerci are straight and unadorned, with a small spine at the tip
– the face has a dark cross-stripe

The Mottled Darner might be easy to identify, but it is a difficult dragonfly to find, an uncommonly encountered odonate at best. It was a real privilege to watch three of these dazzling darners foraging only a half a meter away, flitting just above the water among the emergent rushes near the boat pier (there were others flying further east among the rushes and Pickerelweed, but not close enough to be absolutely certain they were indeed Mottled Darners). The last known encounter in the Tweed area was on September 24th, 2009.

Canada Darner (Aeshna canadensis), Black-tipped Darner (Aeshna tuberculifera) and Shadow Darner (Aeshna umbrosa)

This Canada Darner (Aeshna canadensis) is an immature female, and also a bit cold, so it lacks the depth of color of a mature adult. A large dragonfly, the Canada Darner is about 70 mm long. The photo was taken at Stoco Lake.

Note the styli in this closeup of the terminal abdominal segments.

The notched thoracic stripe is visible in the following lateral views. Also note in the third image that this darner has no facial cross-stripe. The absence or presence of this feature can often be a quick means of sorting out similar darner species in the field.

The exuviae in the next series of images, discovered a few feet away on another tree, likely belongs to the darner above. This find provided an opportunity to obtain pictures of the hinged labium unique to odonate larve.

The colors are pale and the light isn't the best, but the notched thoracic stripe and lack of a facial cross-stripe can be seen in this teneral female, encountered not far from where the female above was photographed.

Darners often forage a fair distance from water and this female lost its bearings and got trapped a window. This is generally game over as the heat will quickly exhaust and kill the insect. The dragonfly was extricated and I took advantage of the chance to capture the beautiful green, turquoise and blue of a mature Canada Darner, after which it was released to continue its journey.

There is a bit of reasonable doubt in my mind as to species and it's possible that these "Canada Darners" are actually the closely related Green-striped Darners (Aeshna verticalis). I haven't had many close encounters with either kind of dragonfly and lack the experience to be proficient at distinguishing the two. Here are a couple of tail end views ... you be the judge.

This male Black-tipped Darner (Aeshna tuberculifera) was the victim of a collision with a vehicle. The thorax was too badly damaged to make out the stripes but enough of the insect's other key field marks remained intact enough to be worth imaging. Black-tipped Darners attain a length of about 70 mm. Note the the cross-stripe on the dragonfly's face.

Views of the claspers and all black terminal segment S10.

This female Black-tipped Darner was encountered along the Eastern Ontario Trail in August of 2008. The female below was photographed perching alongside the trail a few kilometers west of town; again note that S10 is completely black.

I couldn't get any images of the distinctive walking cane shaped thoracic stripes of this male Shadow Darner (Aeshna umbrosa) because it too was hit by a car. The face lacks a cross-stripe although it may show a thin brown line as in this specimen. Shadow Darners are about 75 mm long but relatively slender compared to their other large darner cousins.

The next set of images depicts lateral, dorsal and ventral views of the terminal abdominal segments. In lateral profile the cerci are spatulate with pointed tips, similar to the claspers of the Lance-tipped Darner. However, these organs appear quite different in the two species when viewed from above or below. The Shadow Darner's abdominal spots are greenish and much smaller than in other Aeshna species, giving this dragonfly a dark aspect.