Subject: Monster Robberfly?
Geographic location of the bug: Jones Hole Creek Northeast Utah, near Colorado border
Time: 02:19 PM EDT
Your letter to the bugman: Found this big guy on a hiking trail with my family in north eastern Utah. Kind of looks a bit like like a Robber Fly, but it’s HUGE!
How you want your letter signed : Steven Erickson & Family
We agree that this does resemble a Robber Fly, and being huge is not an exclusionary trait for the family as there are many very large Robber Flies, including the Bezebul Bee Eater, and though the linked image from our archives is not critically sharp, the size of the Red Wasp prey should give you some sense of scale. We were not successful in finding a matching image on BugGuide, which might indicate it is a rarely encountered species due to the remote location, or perhaps it is not a Robber Fly. What we can say with some degree of certainty is that this individual is female because of the space between the eyes and that is blends perfectly with the color of the sand indicating it had adapted well to the environment. We did some additional research on BugGuide on other families in the superfamily to which the Robber Flies belong, Asiloidea, and we feel there are some Flower Loving Flies in the family Apioceridae that look quite similar, but not exactly alike, including this unidentified individual on BugGuide and this member of the genus Apiocera on BugGuide. Our editorial staff is currently out of the office on holiday, but next week when we return, we will consult with Eric Eaton to get his opinion. If we are correct that this is a Flower Loving Fly in the family Apioceridae, then this will be a new category for our archives. Also, in an effort to provide accuracy in the location, we surmise that you mean Jones Hole Creek and not Joned Hole Creek.
Update: We just posted this image of a Stinkfliege in the family Xylophagidae and we can’t help but to entertain the possibility that this Fly might also be a member of that family.
Update: June 16, 2018
After further pondering and a comment from Cesar Crash, we agree that this is most likely a species of Robber Fly.