Readers’ wildlife photos

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).

Next up are some robber flies. The first of these is Dioctria hyalipennis, and it has ironically taken a snipe fly (Rhagio hirtus).

The next robber flies are among our largest species. The one shown first is in the genus Diogmitesand 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.


30 thoughts on “Readers’ wildlife photos

  1. Q: Even immobilized, what does a robber fly do with prey as big as itself? Try eat it there all in one sitting? Or move the body to a more secure location?

    1. They tend to have a favorite perch, which seems selected for giving them a grand view of their surroundings. From what I’ve seen they fly back to that perch. The proboscis pierces between the armor of the prey (usually the neck), and it proboscis is able to firmly hold the prey. Prey size does not seem to be a problem.

      It’s been said before: Robber flies are bad-ass!

      1. Mark, can I suggest something I learned from Andreas Kay for this? He used a Panasonic G9 with 180 frames per second video for his insects. It plays back at 1/6 actual speed. It brings their movements to our speed, and makes them seem far more deliberative and conscious than they seem in real life.

        1. Woa. I do intend to get a M4/3 camera, although I have been favoring models from Olympus. This mainly to catch action shots since both brands of cameras take pictures even before you press the shutter, along with super fast in-camera focus bracketing. Maybe Olympus cameras have a similar slow-mo capability. Heck, maybe my cameras do. They record video. I just never use it.

  2. I wish I could see more flies – especially robber flies. I’ve only happened on one once. They are very noisy fliers.

      1. My yard would actually have that but the hill is steep to get to it and I don’t think I’m up for it. Also the deer flies would bite me so much that I’d return a bloody stump.

  3. Stunning photos. The bee mimic robber fly with its fly prey particularly stands out! What equipment are you using? I would love to try macro photography but it seems a bit daunting.

    1. It hardly matters what equipment one uses, as long as it has 16 Mpx or more, and a sharp lens that has close up capabilities. All cameras in that range are good.
      A used 50mm lens on extension tubes will work wonders. Plus an external flash, and a diffuser on the flash.
      Besides dslr or mirrorless cameras, there are good point and shoot cameras that do quite well. A photographer named Jenn Forman uses a Canon powershot point and shoot, and look at what she does!

  4. Terrific photos. I guess with compound eyes, tilting the head around gives them better orientation? Hard to know what a fly sees.

    1. My guess on the head movements is that although they have a wide field of vision, their forward vision is most acute. So they turn their heads to put their sharpest vision on possible targets.

  5. Those are all excellent pictures of fascinating behavior. The odd thing about these guys is that they lack “heads” as such. Anterior to the abdomen, they seem to be just a pair of eyes affixed to a thin thread. They can’t have much mentality going for them.

  6. @Mark
    Thanks for letting us see those lovely piccies.

    I have a new appreciation for flies,
    esp those robber ones!

    1. Those are called halteres, and all true flies have them. They are balancing organs used for flight, and are descended from hind wings. So most insects have a pair of front and hind wings, but flies have only front wings and their hind wings are now halteres.

  7. just wonderful as always Mark. Flies are a very underrated group of insects in terms of beauty and interest

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