09 July 2009

A Dragon and Two Damsels

Until recently, I didn't have many photos of damselflies and dragonflies. Maybe it's just the fact that I've been in good habitat, but it really seems like these insects have been much more photogenic lately. Here are a few of the species I've seen in the past week.

While in the field in northwest Indiana along the Little Calumet River on July 9, 2009, I heard the familiar sound of a dragonfly drying its wings in preparation for flight. I turned around, expecting to see a very common species like a 12-Spotted Skimmer (Libellula pulchella), Common Whitetail (Libellula lydia), Widow Skimmer (Libellula luctuosa), or Common Green Darner (Anax junius). But when I found the insect, it was obviously none of those. Instead, it was what I believe to be a Cyrano Darner (Nasiaeschna pentacantha). According to the books that I have, this species is uncommon in Ohio and common in Indiana, but not known from the northwest Indiana counties near the lake, where I observed it.

A bit later, a damselfly landed on my pants. For the most part, you can distinguish a dragonfly from a damselfly by the orientation of their wings when they are resting. A dragonfly rests with its wings held perpendicular to the body, while a damselfly rests with its wings above and together. There are a few exceptions to this rule, including spreadwing damselflies and a few others, that rest with their wings out, but spread apart. Another difference between dragonflies and damselflies is that the hindwings of dragonflies are wider than the forewings, but in damselflies, the hindwings and forewings are similar in shape. Damselflies seem much more difficult to identify than dragonflies. Carl Strang of Nature Inquiries has identified the damselfly below as potentially a brown-form female Blue-fronted Dancer (Argia apicalis). See the comments below for Carl's justification of this identification.

Then, on July 11, 2009 in a wet prairie at Round Lake Nature Preserve in Starke County, Indiana, a spreadwing damselfly landed on a nearby stem and posed for me. You can see that, at rest, this damselfly has its wings spread apart, but the hindwings and forewings are of similar shape. I believe that this is a male Slender Spreadwing (Lestes rectangularis). A good field character for this species, which I think I see in my photo, is the pale edge of the wingtips. Slender Spreadwings are common and widespread in Ohio, but from what I can find are only known from 13 counties in Indiana. Most of those counties are in the northeastern part of the state, and it does not appear that the species was previously known from Starke County.

Please feel free to correct me if any of these identifications are incorrect.


Anonymous said...

Hi, Scott,
Great photos. I think cyrano darners probably are more common than people have thought. They hang out in shaded stream edges, and seldom land (you were lucky there). Your dancer I think may have been a brown-form female blue-fronted dancer, Argia apicalis. The thoracic patterning fits that species better, and as best as I can tell from the photo, the dark striping extends onto tiny apical abdomen segment 10, which would rule out tibialis.

Scott said...

Thanks Carl! I appreciate your help.