Subject: rose borer wasp?
Location: Floyd County Virginia
August 6, 2014 11:45 am
Cutting off some sickly stems of my knockout roses, I found the stem (about 1/2″ in diameter) to be hollow inside. I slit the stem lengthwise and found these guys inside. I looked them up using whatever search terms I could think of, but found nothing similar. The wasps (?) are about 1/4″+ in length, and they appeared to be newly “fledged”…just beginning to spread their wings. Perhaps they were about ready to bore their way out, having passed through their larval stage?
Signature: Laurel Pritchard

Small Carpenter Bees

Square Headed Wasps

Hi Laurel,
We didn’t think these seemed like the usual suspects, Small Carpenter Bees in the genus
Ceratina, so we checked with Eric Eaton.  Here is his response.

Eric Eaton identified Square Headed Wasps
These are square-headed wasps, family Crabronidae, and probably Ectemnius continuus.  They nest in pith like small carpenter bees, certain mason bees….but they stock the tunnels with paralyzed flies as food for their offspring.  So, still beneficial, just in a different way.

Square Headed Wasps

Square Headed Wasps


Location: Floyd County Virginia

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