Mon 25 Aug 2008
Insect id?
Posted by Nicole under Field Trips
[5] Comments
Here’s a great one ….. this is straight from the field from our bird walk at BRCES last Saturday. Ray Smith sent this over and we’re interested in knowing what insect this is. Many thanks to Marcia for standing still while Ray got the shot. If you can help id this insect, please do post a comment. Here’s his note:
I was on a bird walk Saturday with the Loudoun Wildlife Conservancy and came across an unusual (at least for me) situation and was wondering if one of you could help me with an ID. Attached is a picture of a scary looking critter clasping, and either sucking the insides out of or laying eggs in another scary looking critter. The claspee appears to be a Bald-face Hornet and the claspor I do not know. Although it kind of looks like a very large fly. Can you ID the claspor? All of you are my best insect ID friends.
Also, if you know it, do you know anything about it’s natural history and what it is probably doing in the picture? Thank you.
Ray Smith
Mystery solved – thanks to Cliff Fairweather of the Audubon Naturalist Society. Here’s his note:
The predator is a robber fly (family Asilidae): this is an interesting family of predatory flies that include some amazing bee and wasp mimics. That this one has taken a bald-faced hornet is a testament to it’s predatory skills!
Another great email from Alonso Abugattas on this insect:
Looks to me to be a robberfly. They grab prey (including bees and wasps, leading to another common name for them, beekillers) with their legs and eat it on the wing or from a tree, sucking the juices out of them. They sometimes set up shop outside hives. They themselves often look enough like wasps that other things leave them alone. Hope that helps.
Alonso
And one more from local naturalist Al Giraldi:
This looks like a robber fly (family Asilidae) My best guess is Diogmites neoternatus. These are ferocious predators often attacking insects larger than themselves. They have, as you have noticed, the fire power to take something as big and nasty as a bald-faced hornet. They will bite. Larvae live in damp soil or rotten wood and prey on other larvae, including their own species.
Ray found it online too – it’s called a Red-footed Cannibalfly:
you can find them at http://bugguide.net/node/view/78753
I looked up the Bald-Faced Hornet and one ironic thing is that it predates on flies. I guess what goes around comes around.