The 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: a brown form;and 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):In 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.
Our 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.
I was enjoying the life above the Duckweed (Lemnaceae) recently, marveling that I’ve never seen so many Eastern Amberwings (Perithemis tenera).There 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. 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.I’m taking a semi-wild guess that these are Black Bullheads (Ameiurus melas); what do you think?The barbels are flush to the sides here.As 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.
Male Common Whitetail (Plathemis lydia). Very distinctive. Here’s another view of another:The tail is slightly bluish, actually. Great example of pruinosity, the waxy bloom (can be blue, gray, or white) on mature odonates, especially males.
Dragonfly season is upon us. During this weekend wanderings in Brooklyn Bridge Park, Green-Wood Cemetery, and Woodlawn Cemetery, I saw Blue Dashers, Eastern Amberwings, Green Darners, Black Saddlebags, Carolina Saddlebags, and the three species pictured here.Twelve-spotted Skimmer (Libellula pulchella) male.Always exciting to see something I don’t recognize. A male Unicorn Clubtail (Arigomphus villosipes). Check out those cerci at the end of the tail. “Typically mud-bottomed lakes and ponds” says Paulson on this species’ habitat, which is right on: various carp were splashing in the murk of Woodlawn Lake.
Flying gold at Big John’s Pond: a Painted Skimmer (Libellula semifasciata).
As November nears, the dragonflies are starting to be very scant above the ground. On Saturday, I saw a single Common Green Darner in Green-Wood. Yesterday, I saw this Shadow Darner (Aeshna umbrosa) at Little Stony Point up in Cold Spring. A new species for me, IDed with help from the Northeast Odonata FB crew. Paulson says this is “usually one of last species of autumn.” Besides a bumblebee, this was the only visible insect there. This afternoon, I saw about half a dozen Common Green Darners patrolling a very sunny lawn in Prospect.