Tuesday, June 1, 2010

Spring Damselflies

... continuing last year's theme of mostly dragonflies and damselflies (but of course anything else that is strange, weird, colorful or interesting is also fair game). Another great resource for odonate enthusiasts is Damselflies of the Northeast by Ed Lam. The author' species accounts and illustrations are excellent, and the book includes range maps.

Judging by the large postocular spots, narrow tapering shoulder stripes, and comparitively small black spot on S2, the mating pairs of damselflies in the following two photos are either Boreal Bluets (Enallagma boreale) or Northern Bluets (Enallagma cyathigerum), in tandem and the wheel position respectively. I can't make an identification to the species level because the insects were not captured to examine the male's claspers and/or the female's mesostigmal plates.

This male Taiga Bluet (Coenagrion resolutum) stood out like a sore thumb among the powder blue damselflies. Although it's hard to tell from a picture Taiga Bluets have a touch of green, making them appear turquoise in the field, and the pattern of the black and blue bands on their abdomens is also distinctive.

The "U"-shaped black mark on S2 was broken or thin or broken on the subject above and on some other individuals I captured, but is clearly visible in the closeup of the specimen below.

The "U"-shaped mark is quite strong on this male.

Mating pairs of Taiga Bluets; the photos can't convey the pale pastel green color of the female.

At a length of about two inches jewelwings are our largest local damselflies. The insect in the first image is an Ebony Jewelwing (Calopteryx maculata); the white pseudo-pterostigma on the wings identify this as a female. The second photo depicts a male River Jewelwing (Calopteryx aequabilis).

Going from one extreme to another in terms of size: at one to one and a half inches in length, Sedge Sprites (Nehalennia irene) are our smallest damselflies. These tiny insects look like green-gold threads as they fly through horsetails and other low vegatation. Although abundant, Sedge Sprites are hard to spot and often overlooked since they stay under cover; they would make easy pickings for the larger odonates and other predators if they ventured forth from the safety of their green shelter.

Two views of a male ...

... three images of a female ...

... and a couple of shots of a mating pair.