Thursday, July 20, 2006

Invertebrates at the Arboretum

As I have noted before, midsummer is a good time for insect watching. Birds quiet down as they spend more time tending fledglings and less defending territory. At the same time, many insects, especially colorful butterflies and dragonflies, are at their most prominent. (This is also a good time to start looking for cicadas.) During my last walk at the National Arboretum, I took a number of photographs of insects. I had meant to get these up last week, but did not get the image editing done. So here are a few now.

Common wood-nymphs are, in fact, pretty common in the woods of the Arboretum. This individual was in the section known as Fern Valley. I have also spotted this species in and around the Azalea Gardens. Despite their overall brown coloration, common wood-nymphs are fairly easy to pick out because the yellow patches at the tips of their wings are quite noticeable in flight.

I think this is an ebony jewelwing. While this damselfly's body appears blue in this photograph, it also appeared green when the sunlight struck it from a different angle. Unfortunately, it did not sit still long enough for an additional photograph at that angle.

Below is a photograph of a female common whitetail. Males are easier to spot and identify since they have whitish bodies and bold black patches on their wings. Females are more dully colored but retain a similar body shape.

Also playing in the mud was a Horace's Duskywing. This is one of the spread-wing skippers (subfamily Pyrginae of the family Hesperiidae). Look at the subtle variations in browns and oranges in this butterfly's wings. They seem to change tone with the angle of the light.

Finally, here is a moth whose identity I do not know. I have to say, though, that I love the intricate pattern of the upper-wings. The blotches at the center of the body look a bit like a face.

If you think any of my identifications are off, please make a note in the comments. My skill identifying insects is not as great as with birds.

For identifying butterflies, I use Ken Kaufman's Butterflies of North America. My favorite site for identifying the odonates is one that specializes in Maryland Dragonflies and Damselflies. (I do not have a book at the moment.) If you have interest in books on this topic, see Hawk Owl's combined review of several titles.