Friday, July 14, 2017

Dragonflies - Some Skimmers

Widow Skimmer - Libellula luctuosa - Male Mature  

Finally a Dragonfly post, first I want to say I am not an expert. I depend on a Facebook group I belong to for most of my identifications.  However, today's post includes three very common Dragonflies, they can be found pretty much anywhere in North America where dragonflies are flying.  These three all have a couple of other things in common, they are all Skimmer Dragonflies and they all (depending on the sex for some) develop pruinescence as they age. Pruinescence is a waxy film usually white.  Skimmers are the largest group of Dragonflies, if you want to know more about them click on the link above.

Now on to today's photographs, above is a mature male Widow Skimmer, the image below is also of a Widow Skimmer, but this one doesn't show the pruinescence of the older Dragonfly. Note how the mature Male Dragonfly has developed white on the wings, blue on the abdomen, and black on the top Thorax.  Females may develop brown wing tips but won't have the white or blue though the thorax and abdomen will darken. I don't have a good photo of an older female.

Widow Skimmer - Libellula luctuosa - Newly Emerged

The next three photographs are of Common Whitetails, note the different wing pattern between males and females. 

Common Whitetail - Plathemis lydia - Male

The male Whitetail above is fairly newly emerged, the white patterning is still visible on the body.

I want to explain what I mean by the comment newly emerged (another term is Teneral). Dragonflies go through a nymph phase that lives in water, when it is time for the adult Dragonfly to emerge the nymph crawls out of the water usually on a grass or water plant stem, and like a chrysalis splits open allowing the adult form to emerge. Like butterflies they need to expand their wings and dry off. As the Dragonfly or Damselfly age they often undergo color changes, pruinescence is just one of changes.

Common Whitetail - Plathemis lydia - Male Mature

 The above photo shows a mature Whitetail where the pruinescence is fully developed. 

Common Whitetail - Plathemis lydia - Female

Above is a Whitetail female, note that her wing pattern is very different from the males. It can be confusing for beginning Dragonfly observers I know I though I had found a different species only to discover that no, it was one I had already identified just a different sex.

Blue Dasher - Pachydiplax longipennis

I have one last example for today's post. The Blue Dasher is another very common dragonfly, and from what I have read one of the most studied. I think they are a rather pretty, certainly more colorful than the other two Dragonflies in this post.

Blue Dasher Mature Male

Above is a mature male Blue Dasher and you can see where the name comes from with the blue abdomen.

One last photograph, not a very good one but I was trying to photograph a female Blue Dasher as she was depositing eggs on the surface of the lake at Ames Nowell State Park. 

Blue Dasher Female depositing eggs

In the case of the Blue Dasher both male and female dragonflies develop the blue coloration.  Correction: I have recently regained access to my one book on Odes, according to this book the females don't pruinose, so I wanted to correct my comments - Sept. 19, 2017.

That is it for today, all photographs were made by me, though not all of them from this year, in local (Southeastern MA) State Parks or other nature reserves.  Per usual comments are welcome.