Friday, August 05, 2011

A Mystery That's Likely to Remain Unsolved

For about a week, we had a distinctive mini-volcano in the garden by our front steps. It was roughly 1" tall, with a hole the diameter of a pencil in the middle of it, and somewhat sheltered by a seedling aster. Every time I walked by, I glanced at it, checking inside the hole for any sign of activity.

And one morning, on my way back from getting the paper, I was rewarded by seeing the tunnel blocked by the large head of an insect. As soon as it saw me, it backed down the tunnel, so I grabbed my camera and waited a few feet away.

Pretty soon I was rewarded by the insect emerging from its tunnel. I managed to capture its head, but by the time I tried to get a second shot of the entire insect as it emerged, it had flown rapidly away. I did not get enough of a look at it to know whether it was a bee or a wasp, or even what the body color was.

I went out several times during the day and waited, trying to see my mystery volcano builder again, but she eluded me completely.

While I was waiting, though, the Carolina wrens who've been nesting on the breezeway decided that I was intruding intolerably on their territory. You haven't truly been read a riot act until you've had a Carolina wren upset with you!

One of the parent wrens became particularly bold, moving from the Bradford pear in the garden to behind the pots on the breezeway to the top of wicker chair just 10' away from me. I couldn't resist capturing the scolding that I was getting on camera.

(As a side note: In capturing this bird on camera, I have to ask if anyone else thinks its beak is somewhat malformed? It seems too long to me, especially the lower mandible.)

Two days later, the breezeway and the garden were both quieter. The wrens appeared to have fledged their young, and the volcano hole had been carefully plugged, reducing the size of the exterior cone significantly. After the rain 2 nights ago, you can't even tell there was ever a mini-volcano there.

One of these days, I'm going to take down the clay wren nest to see if the babies actually made it. One evening about a week before this incident, I had found 2 half-feathered baby wrens, obviously still too young to be out of the nest, on the breezeway floor. It was one of those desperately hot days and I figured the babies had tried to get some cooler air at the entrance to the nest and they'd fallen out. I got a ladder, put them back into the nest, and hoped for the best. Since the parents continued to defend the breezeway for over a week and I did not find any baby wren bodies, I have great hopes that at least one of them survived to fledge at the proper time.

So I will probably get an answer to the wren question, but the identity of the volcano-building bee/wasp is likely to remain a mystery. I plan to post the photo on BugGuide, but with just the somewhat blurry photo of the insect's face, I have little hope that anyone will be able to help me. If I do get an answer, I'll be sure to share it!


~Gardener on Sherlock Street said...

My goodness the drama you have there. I don't know what the insect is either but love the scolding wren photo.

ProfessorRoush said...

Maybe a digger wasp ( or a burrowing mole cricket,Neocurtillia hexadactyla? (see page 2):

Gaia Gardener: said...

I don't think it was a mole cricket, but I do think it may have belonged to the digger wasp clan. My other thought is one of the solitary bees.

Gaia Gardener: said...

I did put the photo up on BugGuide, but haven't received any possible identifications yet. I've searched that site for any matching photos, but I can't come up with any bees or wasps that have those greenish-yellow eyes.

Kitt said...

I love the wren picture! I hope the babies survived.

Your burrower looks like the penultimate photo on this page. So, Tachytes maybe?

Gaia Gardener: said...

Kitt, I think you've got it narrowed down to genus! Thank you! I posted the photo on BugGuide, but haven't gotten any responses from them yet. (It wasn't the best of photos, so I'm not too surprised.)

I'll probably take the wren nest down to check it out (and clean it) sometime this week, after it cools down a bit. If I find anything interesting, I'll post about it.

Thanks again for the link on Tachytes. It fits very well: green eyes, sandy soil, mound of soil by entrance, fast moving when flying into (and, by my experience, out of) the nest. And heaven only knows we have more than enough grasshoppers around this year to raise hordes of baby wasps.