Subject: Robber Fly Identification
Geographic location of the bug: Elkridge, MD
Time: 01:37 PM EDT
Your letter to the bugman: Yesterday, I found a robber fly on the bush outside my house. I’ve never had the opportunity to see one so close, especially while it had found a meal! I’ve been trying to identify what species of robber fly this might be. I think it might be a Red-footed Cannibalfly, but I’m not sure. I’d love some help confirming the species of both the robber fly and its dinner! Thanks!
How you want your letter signed: Renee
We agree that this Robber Fly is a Red Footed Cannibalfly, or at least another member of the genus Promachus, the Giant Robber Flies. The prey is a Leaf Footed Bug in the genus Leptoglossus, and the light tips on the antennae lead us to believe it is likely Leptoglossus oppositus which is pictured on BugGuide, or possibly Leptoglossus fulvicornis, which is also pictured on BugGuide. According to BugGuide, the latter feeds on “Magnolia fruit” and the former “can be very common on catalpa pods” according to BugGuide. Alas, other diagnostic features for the Leaf Footed Bug are obscured by the Red Footed Cannibalfly. Do you have either a magnolia or a catalpa nearby or another camera angle that shows more of the Leaf Footed Bug?
Thank you so much for taking the time to respond to my email! Unfortunately, the only other picture I took was not clear. I know there are Southern Magnolia trees in the neighborhood. I don’t think I’ve seen any catalpa in the immediate neighborhood, but we do have them here in Maryland as well. Just a few days after my first sighting of the Red Footed Cannibalfly, one appeared on the edge of my window that I had the chance to watch again!