The panoply of nature: more bizarre flies

December 13, 2012 • 9:34 am

Flightless flies would seem to be an oxymoron, but there are plenty of them, and they include some of the most bizarre insects on Earth. Just search, for example, for “phorid” on this site.  Some of these creatures are so bizarre, as either larvae or adults, that you’d never take them to be flies.

Get a load of this one.  Matthew Cobb called my attention to a new post by the talented photographer and entomologist Alex Wild on his photography website (see also his great website Myrmecos) showing the larva of a syrphid fly so weird that it was once described as a mollusc (see caption below taken from Alex’s site). It preys on the brood of ants, and I suspect the “tube” at the upper right is for respiration (my Drosophila have a pair of these “spiracles” at their posterior end):

arvae of syrphid flies in the genus Microdon are so odd that they were originally described as molluscs. The adults are more or less normal-looking flies, but larvae are predators of ant brood, living within the dark galleries of ant nests (in this case, with Linepithema oblongum). Termas de Reyes, Jujy, Argentina
Larvae of syrphid flies in the genus Microdon are so odd that they were originally described as molluscs. The adults are more or less normal-looking flies, but larvae are predators of ant brood, living within the dark galleries of ant nests (in this case, with Linepithema oblongum).
Termas de Reyes, Jujy, Argentina

As lagniappe, here’s a couple of very weird flightless flies from site “The Atavism” (and indeed, vestigial wings are atavisms). Remember, these are flies.

Here’s a “sheep ked,” a parasitic flightless fly from New Zealand with The Atavism’s (TA’s) caption:

Flies in the family Hippoboscidae are blood suckers. Many of these parasites fly from hosts to host, but a number of species have become so intimately associated that they’ve given up on flying – moving from one animal to another only while those hosts are in physical contact. The flightless hippboscids are generally called “louse flies” or “keds” and the most well known examples include species that specialise in drinking from pigeons, cattle and sheep.

Note the vestigial, useless wings: a testimony of its evolution from a flying ancestor:

Crataerhina pallida, the sheep ked
Crataerhina pallida, the sheep ked

A parasitic bat fly, again with TA’s caption:

The bat flies have lost their eyes as well as their wings, by have made up for those loses in other body parts. The massive spider-like legs end in tiny claws that let the flies grip on the bat’s fur and move about. Once stuck on a bat these flies drink blood.

Nycteribiidae

Photo by Giles San Martin

Look at those claws!

The anterior leg of a parasitic fly of the familly Nycteribiidae collected on a Plecotus auritus bat in Switzerland (Le chenit, Baume de la petite Chaux, Coll. P. Nyssen). The claws are particularly well adapted  to grab the fur.
The anterior leg of a parasitic fly of the familly Nycteribiidae collected on a Plecotus auritus bat in Switzerland (Le chenit, Baume de la petite Chaux, Coll. P. Nyssen). The claws are particularly well adapted to grab the fur. Photo by Giles San Martin.

And here’s a bat fly from Kenya:

As far as we know, the family Mormotomyiidae is represented by a single species (Mormotomyia hirsuta) which is only known from a particular site in on one mountain in Kenya. As you may have guessed the site is a bat roost, and the animal, despite being only distantly related to the other bat flies discussed above, has taken on the spidery form that is associated with flies that spend their lives with bats.

You’d think this was an ant or something, wouldn’t you? We know it’s a fly because of its other traits that place it clearly with dipterans (and certainly molecular analysis would confirm that).

Photo: AFP (?)
Photo: AFP (?)

There are more of these; go read about them at The Atavism.

h/t: Alex Wild (who’s given me blanket permission to reproduce his work) and Matthew Cobb

25 thoughts on “The panoply of nature: more bizarre flies

  1. Maybe the brown ‘bottle-neck’ structure in the Syrphid larva corresponds to the posterior spiracles of a Drosophila larva?

  2. “my Drosophila have a pair of these at their posterior end”

    I know a good plastic surgeon in NY that can take caere of those.

  3. Wonderful flies!!! I used to see those hippoboscid flies in my former biology department when the dept’s giant python would nom live pigeons (six or so pigeons per meal). As a pigeon would slowly get swallowed by the python, all the hippoboscid flies on the bird would flee to its tail, like passengers on a sinking ship.

  4. The particular sheep ked you show may be from New Zealand, but a little thought will tell you that obligate parasites of sheep can’t possibly be native to New Zealand. Sheep keds, presumably, first climbed onto wild sheep somewhere in the Near East. And we have plenty of native hippoboscids in North America. The flying ones tend to shed their wings after landing on a suitable host.

    Based on aquatic syrphid larvae I’m familiar with, one might suspect that tube is for breathing. And Wikipedia confirms.

    1. Yes, that is a breathing tube. I remember it well, since that is what kept poking out of my arm when I hosted a botfly maggot. Jerry, you probably remember seeing that tube bobbing in and out of your body as your maggot dined….

  5. It’s things like this that make me realize that no other knowledge has provided me with as much awe, wonder, and delight as my (albeit rudimentary) understanding of evolution. Would love to know the evolutionary history of those Microdon larvae!

  6. Whoa. Here’s something else weird I didn’t know about hippoboscids: “Females rear one offspring at a time, the larva feeding in utero from special “milk” glands. The mature larva is “born alive” and immediately pupates in the soil (or on the host in some cases).”

    From the online bug guide.

    1. Tsetse flies do the same thing. Flies (and maggots) are amazing things. Such variety. I will be posting a review of Steve Marshall’s stunning new book “Flies” on WEIT soon (after the Ediacara).

  7. The photo of that fly larva reminds me of a scale insect -Hemiptera, I think. And they’re strange too, in that the adult females are the “scales”, while the males are free-living and often are winged. I’ve been trying to get rid of the buggers off my orchids for years now…

  8. Oh yeah, and not all bat flies are parasitic. The NZ bat fly is wingless and spider-like but is a commensal, found only in the roosts of NZ short tailed bats and lives off their guano, apparently.

  9. I recall from my days prepping birds and mammals in far-away places frequently encountering hippoboscids that would scurry around in the plumage. When prepping bats, there were often the related streblids and nycteribiids.

  10. Crataerhina pallida, the Swift Louse Fly, is an ectoparasite of the Eurasian Common Swift and only a Sheep Ked in the sense that they belong to the same family. The actual Sheep Ked has no wings. Keds and Tsetse have a similar bizarre (for a fly) life cycle because they share a common ancestor with same.

    And just to be even more pedantic, “Flightless flies” would not only seem to be an oxymoron, but is one.

Leave a Reply