What do you call a fly with no wings? If you are someone’s Dad you are probably compelled to answer “a walk”, but, in fact, there are hundreds of species of fly that have given up on flight. What do you call a fly with no wings? Well, it could be a female phoird, or a hippoboscid, or perhaps a Mystacinobia. So here’s a brief survey of a few flies that have taken a brave stand against nominative determinism and given up on flight.
So what is a fly
Diptera means “two winged” and the name refers to the fact that most flies get about with one pair of wings, having reduced their second set into the flight-satablising halteres. This little innovation has allowed dipterans to become precision fliers, and one of the most successfully groups of organisms on earth with about 150 000 species (maybe 10% of all species are flies).
The true flies in order Diptera all descend from an ancestor which flew with two wings, but many of the species that descend from that ancestor have given up their wings. Because taxonomic groups are reflections of evolutionary history even wingless species are still flies – you can call them the apterous members of Diptera (wingless two-winged insects).
Bat flies, Bat flies, Bat flies
Bats seem to attract flies like… well they seem attract flies. At least three different lineages of flies have evolved a close relationship with bats. The largest group are, unsurpsingly, called “bat flies” (the taxonomy of this group is uncertain, but it includes the family Nycteribiidae). I have a soft-spot for most bugs, but even I have to admit bat flies are pretty gruesome looking creatures:
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.
The fauna of New Zealand is very keen of flightlessness. Charasmatic mega-fauna like moa, kiwi and kakapo are the obvious examples, but we are also one of only two places on earth to have flightless perching birds (our three wrens are now extinct, as is the Canary Island Bunting). There are no truly flightless bats, but our short tailed bat is probably the closest thing – spending most of its time crawling around the forest floor. Our terrestrial bat hosts its own flightless flies. Apparenlty Mystacinobia zelandica descends from a blowfly but its association with the short talied bat has changed its body so greatly that is was not originally considered to be a fly at all, and thought to represent a unique order of insects. I couldn’t find any photos of Mystacinobia avaliable with a permissive license, but check out the New Zealand Geographic story and Te Ara’s article, which even has a video.
Mystacinobia has been placed in a family that is endemic to New Zealand, but there is one fly family with an even more restricted range. 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.
Mormotomyia doesn’t have the hooks that other species use to cling on to bats, so it may be a little more free-living than than the species discussed above.
Photo from USDA (public domain)
A.lubbockii is a parasitoid of ants, the females live within an ant nest and lay eggs in the ants pupae. It is though that the rounded body, with relatively few jointed segments for ants to hang on to, helps them move around within a nest. But, of course, for that to work females need to be able to move on from the nest in which they are born. That’s where the winged male comes in, A. lubbockii males airlift their females into ant nests. The males pick up females and carry them, mating on the wing, before dropping them off to infiltrate a new nest.
So, so many more
That looks nothing like a fly. How come this evolved into a ‘walk’ ? It makes no sense. If I could fly I wouldn’t evolve into something flightless. Evolution is flawed
The description and photos of A.lubbockii came from
Dupont S, Pape T. 2007. Fore tarsus attachment device of the male scuttle fly, Aenigmatias lubbockii. 8pp. Journal of Insect Science 7:54, available online: insectscience.org/7.54