Thursday, June 6, 2013

Brook Snaketail -- Pennsylvania's First

The Pennsylvania Game Commission recently acquired a large tract of land on the north face of the Kittatinny Ridge in southern Monroe County. This property, once slated for development, contains a variety of habitats including a sedge and alder wetland that borders the Aquashicola Creek. This habitat looked like an excellent place to search for dragonflies, so I headed down there with my net and camera in hopes of finding some interesting species.

Sedges, cattails, and alders (in back)
While walking through the sedges, I found numerous Ashy Clubtails--a very common species this time of year:

The sedges also held many Calico Pennants and Twelve-spotted Skimmers. Once I worked my way through the sedges, I decided to focus my search close to the creek where it would be easier to see and catch the insects. Here I found many more Ashy Clubtails as well as hundreds of Ebony Jewelwings.

male Ebony Jewelwing--a type of damselfly
I soon spotted a large dragonfly with a distinctive green color, unlike the other species I had been seeing. I netted this individual in order to get a closer look:

This green, black, and yellow dragonfly is a Maine Snaketail, a species that inhabits rocky streams. This species is ranked as an S2S3 species within the state by the Pennsylvania Natural Heritage Program, which means that this is a rare species in Pennsylvania.

Not long after catching the Maine Snaketail, I spotted another dragonfly that appeared to be similar. In fact, when I saw it flying, I figured it might be of the same species. However, closer inspection suggested that was not the case.

The general appearance is very similar to that of the Maine Snaketail, but there are few differences in coloration and a distinct terminal appendage shape. Examination of the male's terminal appendages can be extremely helpful when identifying dragonflies. Notice the difference in shape of the appendages between the Maine Snaketail and this individual:

Maine Snaketail--note the two distinct "spines" on the lower appendage
On this snaketail, note the single spike on the lower appendage and the different shape of the upper
When I got home, I was able to research this species and determined it to be a Brook Snaketail (Ophiogomphus aspersus). After consulting a few experts, my identification was confirmed. I also discovered that this is a species that had never been recorded in the state of Pennsylvania before! 

I can't wait to get back to these game lands to see what other species may be hiding there!


Julie Zickefoose said...

Holy cow, Corey! A first of state dragonfly?! What else will you discover? I don't know if I'm more amazed that you can actually catch these things, or that you can produce such amazing macro shots of their, um, terminal appendages. Really cool. Are you working with two camera bodies, one with a macro lens, to do this? Tell me true. And congratulations on the new Brook Snaketail! That would be a good name for a film noir heroine.

Corey Husic said...

Julie, I just use one camera body with a 100mm macro lens for things like this. All of the shots in this post were taken with that lens--it's amazing for close-ups, but also very sharp when backed out.