Robber flies are of the order of Diptera (Flies). They only have one set of wings like all flies. All in the family Asilidae (Robber Flies) are predators of other insects. They are aerial hunters. In fact, I watched one try twice unsuccessfully try to catch a Great Golden Digger Wasp (Sphex ichneumoneus). There are around a thousand native species in North America alone.
This robber fly was a recent visitor out my back door. It seems to be mimicking a wasp.
Here is a side view. No thin wasp waist.
Of course, I had my suspicions above that it was not a wasp. However, when I got a look at its beard, that nailed as a robber fly. Its prey was a black blister beetle. The beetle had been chomping on the tomato leaves, so thanks robber fly! A BugGuide expert said the robber fly is Prolepsis tristis.
Next, a head banger! This robber fly repeatedly rammed its head against the window. Indeed, it must have taken lessons from the male cardinal we have had here this year. In the same way the cardinal thinks it has competition, maybe it thought the same?
Robber fly snags robber fly! Ok, it is a different species. So robber flies take a variety of insects from butterflies, beetles, flies to mention a few. The larger one is a Giant Prairie Robber Fly (Microstylum morosum). It is a rather large robber fly that measures about 2 inches. In fact one source said that genus is the largest in size in the US. NatureServe says it is vulnerable in Arkansas.
Unfortunately for the Giant Prairie Robber Fly, it dropped its prey. Usually, most robber flies I encounter with prey take their meal with them. Not one to pass by such an opportunity, the prey came home with me. Accordingly, it got the full studio experience. đ BugGuide experts say it of the Saropogon genus. Thank you BugGuide!
Like most all robber flies, it has a beard. In addition, in this photo you can see its modified stiff proboscis. This is used to inject its prey with neurotoxins and digestive enzymes to make a yummy soup meal contained in the exoskeleton of the prey. Yum!
So the predator became the prey. Here a female jumping spider (Phidippus clarus) snagged a robber fly (Diogmites)!
On occasion, you might run across a robber fly that mimic a bumble bee! The front yellow legs of the Laphriaaffinis is diagnostic for this species. (June 3, 2020)
Last year, I found this really tiny five millimeter robber fly. I narrowed down its ID to Hadrokolos texanus or Holopogon snowi, both are in Texas. (August 2021) Thus we seem to have the tiniest to the largest robber flies in the US right here!
So from the tiny to large, the amazing Robber Flies (Asilidae) are a welcome addition to our wonderful North Texas ecosystem. Moreover, I hope you think so too!
What incredible photos of the murder and mayhem going on in the garden. Insects are absolutely fascinating!
Mike, only the first species was in my little garden. The rest were out and about. But yes, life and death are definitely exciting!
Wow, what a cool post! Amazing photos of the predator/prey interactions!
Thanks!đ