Ugliest Wasp EVER
Location:  North Texas
August 14, 2010 6:30 pm
Can you tell me what kind of wasp this is? This wasp will attack flying insects in the air,and if it catches them, seems to attach itself behind the insects head. Sucking out vital fluids perhaps? Also, when this wasp flies, it makes itself appear larger by keeping forelegs up above it’s head. Today one caught a bumble bee of which is in a couple of the photos.

Robber Fly eats Bumble Bee

I do not know how it nests, I only notice these individually, on my blooming plants just waiting for a chance to catch something.
Curious about the ugliest insect I have ever seen.

Robber Fly

Dear Curious atuiIhes,
This is a Robber Fly, and it is one impressive creature.  It looks very similar to the Hanging Thieves in the genus Diogmites, but not quite.  We searched BugGuide for related genera, and it most resembles members in the genus Saropogon, but there were no matches on BugGuide.  By doing a web search for Saropogon, we discovered the Key to the Saropogon of the United States page, and the description that seemed closest to your specimen is Saropogon birdi.  We searched that and came up with a photo on Flickr that looks identical to your specimen.  We also located a Midwest Biological Control News page entitled Know Your Friends with this tidbit on another member of the genus Saropogon:  “
Saropogon dispar is the most injurious of a number of species in Texas that frequent apiaries — more than 700 of these flies were destroyed in one bee yard in a period of three days!”  We are relatively confident your Robber Fly is in the genus Saropogon, but we would like to try to consult an expert in the family for confirmation.  We will see if Eric Eaton can recommend a Robber Fly expert.

Robber Fly

Thank you very much for getting back to me. After submitting the photos I looked at your bug of the month and kind of figured it out although I thought it was a hanging thief, it just didn’t hang.. lol    The next day I was out taking pics of butterflies, and one of the robber flies landed on my camera, I almost dropped the camera.. It was probably just trying to be friendly. Right!  Anyway, thank you so very much and I will be happy to know exactly which robber fly this is.
Rhonda, still slightly curious. 🙂

Update on Identification
August 17, 2010
Hi Rhonda,
We are still waiting to hear something from Robber Fly expert Dr. Robert A. Cannings, Curator of Entomology at the Royal British Columbia Museum who we emailed after posting your letter.

Update from Dr. Robert A. Cannings
August 18, 2010
Hi Daniel:  I don’t know Saropogons well, although I think you are
correct in assuming this is one. I’ve sent the photos to Eric Fisher in
Sacramento to check but he hasn’t replied yet. I’ll let you know when he

Update:  confirmation of Saropogon
August 26, 2010
Daniel, Eric Fisher says it looks like Saropogon combustus. So there you

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