Arboretum: Eastern Comma and Pigeon Tremex

I saw a few moths, butterflies, and wasps at the Arboretum last week. An eastern comma butterfly (Polygonia comma) rested on a leaf in the shrub and vine garden. It is named for the bright white comma, swollen at both ends, on its wing. I think it looks more like a crescent moon than a comma.

Eastern comma butterfly with wings closed
Eastern comma butterfly

The wings look drab until they open, revealing a rich orange with black spots. This is the winter form of this butterfly, with its hind wings more orange than black.

Eastern comma butterfly opening its wings
Eastern comma butterfly

An armyworm moth (Mythimna unipuncta) wasn’t succesful at hiding itself in tall, green grass. In addition to a furry top, they have a bright white spot on each wing that has two black dots on either side of it. It is also known as the white-speck. Thanks to Maury Heiman on BugGuide for the ID.

Armyworm moth
Armyworm moth

Here’s the moth staring straight up at me. It appears to have a purple stain on its mouthparts.

Armyworm moth face
Armyworm moth

I found two more moths, neither of which I could identify to species. One is a grass veneer moth and the other I found on the trunk of a maple tree.

Grass veneer moth
Grass veneer moth
Moth on maple trunk
Moth on maple trunk

I saw a crane fly. Every time I post one of these creatures to BugGuide, they are immediately moved for expert attention. Must be difficult to identify them to species.

Crane fly
Crane fly

I found an ichneumon wasp loitering in the grass. It had a black head, black and yellow legs, and smoky wings. Ross Hill on BugGuide identified it to the genus Therion.

Therion wasp
Therion wasp

It had a thin red abdomen that ended in a thick black ovipositor that reminded me of a muffler.

Therion wasp showing ovipositor
Therion wasp

As I was walking by the zelkova collection, I saw a horntail wasp trying to lay its eggs in a zelkova tree. It was too high up for me to get a good look, but I believe it is a pigeon tremex (Tremex columba).

That stub you see sticking out its behind is why it is called a horntail wasp. But that’s not what it uses to lay its eggs. See the black needle emerging from the middle of its abdomen? That’s the ovipositor.

Along with eggs, the wasp deposits a wood-rotting fungus in the tree. The larvae eat both the fungus and the wood digested by it.

Pigeon tremex wasp laying eggs in zelkova tree
Pigeon tremex wasp

Wasps are fascinating!

This entry was posted in Nature and tagged , , , , , , , , , , . Bookmark the permalink.

Comments are closed.