Not one for Dragonflies

Ken Ramos · Post by **Ken Ramos** » Sun Apr 20, 2008 6:09 pm

For me to photograph a dragonfly is quite rare. Mainly because I just don't encounter many of them, maybe two or three a year where I live. So an ID would be greatly appreciated, since I searched through Bugguide but must have missed it, if indeed it were in there. Though it more than likely is.

Canon EOS 20D
Manual mode
1/250 sec. @ f/13 ISO 400
Canon EF-100mm f/2.8 Macro USM
Daylight
PP: Photo Impact 6

MacroLuv · Post by **MacroLuv** » Mon Apr 21, 2008 8:17 am

Nice capture Ken.

It looks like a Cordulegaster boltonii in my opinion but not take it for sure.
Better counsult Erland.

Erland R.N. · Post by **Erland R.N.** » Mon Apr 21, 2008 8:38 am

Ken, I love the challenge of doing ID on dragonflies.

A great photo you got there.

It is surely a dragonfly from the Cordulegastridae family. They are the only species where the eyes just touch each otther in a "single point".
The females from the family got a long oviposior at the end of the abdomen (not in this photo), but I think this must be a male. The ovipositor gives the genus Cordulegaster its common name Spiketails.

You are blessed with quite some Spiketails in eastern USA (7), and only one in the west. This is due to the arrid conditions in most of the west, and this family's habitate: streams and other kind of running waters. Often narrow and fast flowing.

ID is difficult for me, as I do not know this genus very well, but I think it must be Cordulegaster maculata, Twin-Spotted Spiketail, which range from northern Florida to Canada. Northern populations should have green eyes like shown here, and not blue as the southern ones.

I think the spots on the abdomen, makes my ID correct, although a picture of the complete insect might help. The species is a "spring-species", unlike most Spiketails.

I'll be back if I realise my ID is wrong

Erland

Erland R.N. · Post by **Erland R.N.** » Mon Apr 21, 2008 8:49 am

MacroLuv wrote:Nice capture Ken.
It looks like a Cordulegaster boltonii in my opinion but not take it for sure.
Better counsult Erland.

You are close

In Europe we got two groups of Cordulegaster species, The C. boltonii group and the C. bidentata group.
Many of the species are quite local, which is why they have evolved into several closely related species with origin in the mentioned "group-species".

My newly revised homepage on dragonflies, feature a picture of C. boltonii on the welcome page.
http://home1.stofanet.dk/erland_refling ... nflies.htm

Ken Ramos · Post by **Ken Ramos** » Mon Apr 21, 2008 10:48 am

Here is a full body shot for reference. I am holding out for a positive ID before I save it to disc. In the meantime I will take what you guys have given me and run with it to see what I can find. Thanks guys!

Took a quick look on Bugguide using your suggestions. Looks to be a Twin-Spotted Spiketail.

Erland R.N. · Post by **Erland R.N.** » Mon Apr 21, 2008 5:05 pm

It's a male.

I've had a second look, and am pretty sure about the species.
The flight season for all but two species should not start before june or late june.
Similar species would not have two seperated spots on the first abdominal segments, but rather a connected yellow line across at least segment 2 (closest to the wings). Most other species have very different spots on the abdomen, mainly much more large yellow areas.
The males are described as having a brown forehead (in front of the eyes) and a yellow face.

Erland

Ken Ramos · Post by **Ken Ramos** » Mon Apr 21, 2008 5:24 pm

From what I can gather, they like small, clear, cold, slow running streams, which is what I have about 100ys. or a little less, in behind where I live. I will have to keep an eye out for more of them, there maybe other species around too. Like I mentioned, I don't get to see to many but now I have an idea as where to look for them. Thanks Erland!