Today we have some lovely fly photos by regular Mark Sturtevant, whose captions and words I’ve indented.
Here are more pictures of insects from the previous summer. Innocent times. This set shows some examples of flies from two related families: the snipe flies (Rhagionidae), which are described as predatory on insects although I have never seen them eating anything, and the robber flies (Asilidae) which are most definitely predators. Anyone who observes robber flies will not have to wait long to discover this about them.
We start with the marsh snipe fly (Rhagio tringarius).
The small snipe fly in the next picture is Chrysopilus quadratus. The relatively large compound eyes identifies this individual as a male.
Several species of snipe flies are especially colorful. The next two pictures show the ornate snipe fly (Chrysopilus ornatus). The first picture is stacked from two hand-held pictures, but I particularly like the second picture. It is recommended that readers enlarge it to admire the posh undercarriage of this beautiful fly.
My favorite snipe fly is our largest, but it is pretty hard to approach closely. This is the golden-backed snipe fly (Chrysopilus thoracicus).
The next robber flies are among our largest species. The one shown first is in the genus Diogmites, and note those sinewy legs! Asilids in this genus are commonly referred to as “hanging thieves” because they hang from foliage by their front legs while eating prey. An interesting example is in the linked picture.
Another group of large Asilids are in the genus Efferia. The one shown here is eating a small bee.
Many Asilids are described as “bee-like” robber flies since they mimic bees. A very small species in this group is shown first (Laphria canis), and it too is eating a bee. Asilids often prey on bees! This one may be a mimic of the small carpenter bee.
Finally, our largest bee-like robber flies are mimics of bumblebees. I think the one shown in the next picture is Laphria sacrator, and it was repeatedly launching from its perch to chase after flies. It eventually nabbed one out of the air in front of me.
An interesting thing about the bumblebee mimic robber flies is that when on the look-out for prey they will often start swiveling their heads sharply up and down and left and right. I’ve been trying to get pictures of this, with limited success. The next picture is a short gif animation of a different species of Laphria and you can sort of see it turning its head if you use a little imagination.
But what I’ve got so far of head-turning robber flies is just this low quality final picture which was taken many years ago.