Is a fly without wings called a walk? Ask an entomologist this dusty old riddle, and you might get a more
serious answer than you expected. Houseflies, horseflies, gnats, mosquitoes and a variety of other tiny,
buzzing creatures all belong to the order "Diptera," latin for "two wings." Uniquely among insects, the rear
pair of wings in the Diptera are greatly reduced into knob-like balancing organs called halteres, giving the
appearance of only a single pair. Some flies, however, take this shrinkage a step further; like the emu, kiwi
and Steven Weber, apterous (no-winged) flies are those species that have ceased to rely on wings in favor
of a more grounded, more niche existence.
|Photo by Wolfgang Kairat, found through Wikimedia commons
Some species of the Hippoboscidae or "louse flies" are fully winged and capable of at least bumbling flight,
but in many, the wings are uselessly stunted and occasionally even absent. In others, the wings may be
used to locate their first host but eventually break off as they rub against an animal's fur. No species is
known to infest humans, but they are a common livestock pest. Those that attack sheep are commonly
known as "sheep keds" or "sheep ticks," for their extremely tick-like lifestyle, clicking to the flesh with their
flattened, heavily armored bodies.
The only entry here that doesn't live on some other animal, Chionea are part of the crane fly family, and
among those rare insects at home in the ice and snow. In fact, these insects are naturally attracted to the
coldest temperatures they can find, and can be found at some of the highest altitudes of any macroscopic
animal. Use of wings would not only get them blown away in powerful winds, but quickly expend energy and
heat in fatal amounts. Adults drink water from ice but are not known to eat, while larvae feed on dead
vegetation, moss, lichen and animal droppings.
Braula caeca is a fat, hairy monster barely larger than the head of a pin, and has adapted to live
exclusively on the bodies of social honeybees. When hungry, it climbs down to the bee's face and gently
tickles an area near its mouth parts, perfectly imitating the signal another bee or bee larva would use to
say "I'm starving, please regurgitate into my mouth." As a reflex action, the bee has no choice but to spit up
the sweet nectar stored in its crop. The majority of the food is wasted, and multiple Braula can significantly
shorten a bee's lifespan, causing a sort of bee bulimia. Beelimia?
Our second weirdest walk is also the tiniest - with only a single, small image and precious little information
available on the whole wide internet.
Wingless females of this species Wandoleckia achatina are pinhead-sized residents of the giant land snail,
Achatina achatina, living in and feeding harmlessly upon is coating of mucus. Little is known of their life cycle,
except that males are winged and live away from the snail's body, probably only seeking one out long enough
to mate. Both larvae and adults probably spread whenever one snail touches another or passes over an
infested slime trail.
|Photo copyright Rod Morris
With their greatly reduced heads, ant-like abdomens and elongated, spider-like legs, Mystacinobia zelandica,
the New Zealand Bat Fly, is a fly with such unconventional anatomy that it was once mistaken for its own
unique order of insects.
Spending most of their existence on the bodies of bats, these wonderfully weird creatures have abandoned
flight in favor of a free ride from their fuzzy hosts, no doubt laughing derisively as said hosts consume
thousands of their winged mosquito cousins on a nightly basis. Curiously, the insect-eating mammals tend to
ignore the presence of potential food climbing all over them, and the arrangement may be a beneficial
symbiosis for both parties. The bulk of a bat-flies diet consists of dirt, dead skin and especially fecal matter
stuck in their host's fur, making these organisms tantamount to bat toilet paper.
Remember never to ask Bruce Wayne to use his bathroom.