Posts Tagged 'dragonflies'

Future Odes

Perithemis teneraEastern Amberwings (Perithemis tenera) in the reproductive wheel: the male holds the female by the back of the head; the female curves her abdomen up and forwards his genitalia, located (counterintuitively?) at the base of his abdomen. Pachydiplax longipennisA female Blue Dasher (Pachydiplax longipennis) dipping her abdomen down to lay fertilized eggs in a bit of water floating on a lily. Enallagma civileIn some species of Odonates, the male will continue to hold the female after mating and through the egg-laying process, precluding another male from mating with her, as with these Familiar Bluets (Enallagma civile). They can fly in tandem like this. Some species’ males will scoop out a previous male’s sperm from the female before adding his own with his specially equipped penis.Pachydiplax longipennisBlue Dasher females don’t seem to need chaperones. And look at all the eggs! Like pieces of short-grain rice, but much smaller. Of course, you know many will not make it to adulthood. These eggs were another post-photo discovery.

Venation

Libellula vibransMale Great Blue Skimmer (Libellula vibrans).Plathemis lydiaCommon Whitetail (Plathemis lydia) male.Libellula pulchellaForewings of female Twelve-spotted Skimmer (Libellula pulchella). I found this with a little bit of thorax exoskeleton a few blocks from home. Extremely lightweight, and prone to blowing away in a weak breeze.Libellula pulchellaSome magnification. Tramea lacerataBlack Saddlebags (Tramea lacerata) female. Hindwings are especially wide on this species.

Hanging the Night

Libellula pulchellaThis Twelve-spotted Skimmer (Libellula pulchella) was parked just off the path around 730pm, so I think it was roosting for the night. The black markings looked velvety in the light.Libellula pulchellaThis is a mature male. If you counted the white spots, too, he would be a twenty-spotted skimmer. To matters more confusing, this species used to be known as the Ten-spot… can you guess why?

Common Green Darner

Anax juniusA male Common Green Darner (Anax junius), one of our largest species of dragonfly. You should really click on the picture for a larger view, since there is some great detail here because this one perched quite a while below eye-level, allowing us all good looks as he rubbed his front legs over his eyes. Note how large those eyes are: dragonflies are like raptors, depending on vision to hunt. A migratory species, this three-inch long darner is usually the first dragonfly seen in the spring and one of the last in the fall (a female is pictured in the link).

Swift Dispatch

Pachydiplax longipennisThis Blue Dasher (Pachydiplax longipennis) gobbled his fly prey up with startling swiftness.

Damsels & Dragons

Argia apicalisThe Blue-fronted Dancer (Argia apicalis). One and half inches long, found along the Bronx River and further away on woodland paths. I’m getting better at distinguished these wee things, which means getting closer with lens of varying sorts. This is a male. Species IDs include the black hair-line markings on the thorax and the blue of the last three segments of the abdomen (compare with the slightly smaller Azure Bluet below). I saw two other damsels on the same paths and figured I had at least two species between the three different types, but it turned out that there are two variations for the female: Argia apicalisa brown form;Argia apicalisand a blue form. Note the absence of a colorful final trio of segments on the abdomen; there are instead tan lines on top and side of segments 8 and 9. Ed Lam’s Damselflies of the Northeast remains the single best source for nailing the identity of these slender flying jewels.

Single click on these images to get larger versions for more detail.

The Odonata, the order of insects that is made up by damselflies and dragonflies, have ten segments to their abdomens, counting from the thorax. Here’s a male Azure Bluet (Enallagma aspersum):Enallagma aspersumIn this species, segment 7 is extensively blue, a tell-tale mark. Note also the much wider mid dorsal stripe on the thorax and the large eye spots.
Perithemis teneraOur smallest dragonfly is the Eastern Amberwing (Perithemis tenera), which is actually smaller, length-wise, than many species of damselflies. But note this thick, thick abdomen: very dragonfly, that, and especially so in the females, as here. This seems like a boom year for the species. Notice, though, that almost all the ones flying low over the edges of local waterbodies are male, staking out their territory and defending it. Their territory: good egg-laying sites. The females, who have splotchy instead of amber wings, are usually found elsewhere, for instance, up in the meadows as in this case, until they venture down for a bout of the ol’ oingo-boingo.

Freshwater

Perithemis teneraI was enjoying the life above the Duckweed (Lemnaceae) recently, marveling that I’ve never seen so many Eastern Amberwings (Perithemis tenera).Pachydiplax longipennisThere were also a few Blue Dashers (Pachydiplax longipennis), making more Blue Dashers.A damselfly of unknown provenance was depositing eggs.

And then, along the edge of the lake, some disturbance from below. There was an agitated simmering, not quite bubbling. I wondered what it might be. Then, rising, a mass of little black fish, tightly clumped together at the surface, swarming over each other, some half out of the water momentarily. They were feasting on something. fish The individual fish visible on the edges of this mass had serious whiskers, barbels, making me think of some kind of catfish. What the hell, I took the plunge.fishI’m taking a semi-wild guess that these are Black Bullheads (Ameiurus melas); what do you think?fishThe barbels are flush to the sides here.LemnaceaeAs an added benefit of my open-handed catch and release, the underside of the Duckweed, some of the smallest flowering plants anywhere, is revealed as purple.


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