Arkansas Dragonflies (Anisoptera) in Sebastian County
What drives an old, retired math teacher to daily brave the heat, humidity, ticks, chiggers, mosquitoes, and biting flies that comprise an Arkansas summer? A love of photography, nature, and especially dragonflies. I am fascinated with these darting, cruising, hovering, perching, feisty, and fierce predators wherever I encounter them: in a field; in woods; by a pond, stream, or river.
The intent of this site is not primarily educational. I'm no expert, and there are many fine books and websites devoted |
to the subject (I'll include some on a reference page at the end). Additionally, some species are difficult to identify with but a picture. Instead, I wish to share my photographic efforts and show the rich variety of these wonderful creatures in my part of the state (Sebastian County).
The building of this site will be ongoing. There are so many dragons I have yet to meet. I'd be happy to answer what questions I can. Last updated: 11/1/16 [email protected] New dragon: see Checklist http://artigerbeetles.weebly.com http://billpix.weebly.com |
Dragonfly Anatomy
![Picture](/uploads/2/1/3/6/21360890/1372911160.jpg)
abdominal appendage - appendage at tip of the abdomen (tenth segment). males have three; females have two. female appendages are often shorter.
abdominal segment - each dragon has ten.
antenna - two, and quite small.
clypeus - the middle third of the "face."
compound eye - can see up to 40' and in polarized light.
frons - the upper third of the "face."
labrum - the bottom third of the "face."
mandible - toothed structure for biting and chewing.
nodus - slight notch in the front (anterior) edge of wing.
stigma - colored cell at the front of each wing tip. found in most dragons.
tarsal claw - found in pairs at the bottom of the third part of the legs.
thorax - heavy part of the body. contains the flight muscles, four wings, and four of the six legs (other two on the prothorax - a structure like a neck.)
abdominal segment - each dragon has ten.
antenna - two, and quite small.
clypeus - the middle third of the "face."
compound eye - can see up to 40' and in polarized light.
frons - the upper third of the "face."
labrum - the bottom third of the "face."
mandible - toothed structure for biting and chewing.
nodus - slight notch in the front (anterior) edge of wing.
stigma - colored cell at the front of each wing tip. found in most dragons.
tarsal claw - found in pairs at the bottom of the third part of the legs.
thorax - heavy part of the body. contains the flight muscles, four wings, and four of the six legs (other two on the prothorax - a structure like a neck.)
Mating
A male dragonfly clasps a female behind her head with his terminal appendages (claspers). The male transfers sperm to a sperm storage organ under his second segment. They land on a small branch or plant, and the male supports them while the female grips his abdomen with her legs and swings the tip of her abdomen under his body to reach the sperm location. The "wheel" thus formed is unique to Odonata. Copulation can last for a short or long while.
At times I excitedly (doesn't take much to excite me anymore) encounter an unfamiliar dragon and think I have found one to add to the list. It usually turns out, however, that it's simply an immature specimen. It might be a newly emerged adult (teneral) or one further along but not yet a mature adult. Here is an example:
Feeding
![Picture](/uploads/2/1/3/6/21360890/2841632.jpg?416)
An Eastern Pondhawk noshes on a damselfly. For another
example, click on the Clubtail tab.
Obelisking
When a dragonfly perches on a leaf, twig, or what have you, on a hot, sunny day, he often lifts his abdomen and points his tail skyward. This is called "obelisking" (an obelisk is a stone pillar, having a square/rectangular cross section and a pyramid-shaped top, used as a monument/landmark.) It's unclear why dragonflies do this, but a reasonable conjecture is they do it to
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minimize the surface area exposed to the sun. Or it may just be some funky dragonfly ritual.
A Blue Dasher (left) and a Checkered Swiftwing (above) engage in the process of obelisking. The Checkered was not found in Sebastian County- taken 6/7/16 in Franklin County, Arkansas. |