Super Fly: The Unexpected Lives of the World's Most Successful Insects

by Jonathan Balcombe

the rhinoceros-stomach botfly is one of Africa’s rarest insects. It also happens to be one of Africa’s bulkiest flies, reaching nearly two inches. If the black and white rhinos disappear altogether, the likely extinction of their botfly parasites would not be without precedent.

He learned that botfly lesions never become infected and usually heal cleanly. He also knew of at least two biologists who had raised botfly maggots to pupation. Motivated by a scientist’s curiosity and miffed at Dr. X for having taken his parasite without asking, Rob informed Dr. X that he was going to keep his last larva, thank you very much.

Rob told me that the larva’s exit wound healed quickly and is now invisible, whereas Dr. X’s incision left an enduring and obvious scar.

The adult male botfly that emerged from Rob Voss’s back, perched on its pupal case. (© DAVID GRIMALDI)

scuttle flies, of which more than 200 species make their living by infiltrating the lives of their distant ant cousins.

Because an ant’s head must be large enough to accommodate a maggot that grows to several times its original size during its residence, scientists have speculated that small size might be advantageous to ants by making them too tiny to be a suitable fly target.

malaise trap (which uses fine meshing to funnel flying insects into a bottle of preservative)

How often do ants’ bodies get invaded by scuttle flies? It varies widely by species, location, and time of year. It can exceed one in three ants, but I doubt that higher rates would be sustainable, because flies depend on healthy ant populations to infiltrate.

Parasitism rates were 1,042 ants (1.6 percent) of the first species and 1,258 ants (5.4 percent) of the other. In very rare instances—five out of nearly ninety thousand ants—larvae of two different fly species emerged from the same ant.

Ant parasitism by satellite flies is serious enough to have spawned an arms race of sorts.

minims (the term given to the tiny hitchhiking workers)

The prod casts a mysterious spell on the termite, who now follows the fly on a long walk. Far away from the safety of the colony, the termite is somehow immobilized by the fly, who then lays an egg in its abdomen, covers it with soil, then guards her comatose and paralyzed victim.

family Asilidae, commonly known as the robber flies.

robber flies use an ambush hunting strategy, perching on the ground or low-lying vegetation then zipping out like a guided missile to nab any suitable-looking prey that happens by. They do not attack from behind, but instead intercept the prey by anticipating its location, as a quarterback does a receiver.

dangling from vegetation by one foot while dining on, say, a bee or dragonfly. It isn’t known why they do this,

World Robber Fly Day,

Fruit fly larvae are commonly infected by parasitoid wasps, who inject eggs into the seemingly helpless grubs with a needle-like ovipositor.

Infected flies mount an immune response termed cellular encapsulation, in which fly immune cells form a multilayer capsule that entombs the implanted egg inside a hardened, impermeable shell.

the dark, dormant oval mass it becomes is still visible in the adult fly’s abdomen after its innards have undergone the dramatic rearrangement during larva-to-adult metamorphosis.

In small organisms that evolve rapidly due to short generation spans, adaptive traits may arise more quickly in a dynamic process of push and push back.

Wasps are evolving chemical virulence factors that suppress the flies’ cellular encapsulation.

Probably due to their habit of feeding on fermenting fruit, they have developed a tolerance to alcohol, and it turns out t...

Fly larvae who have imbibed are less likely to be a...

Alcohol consumption can even zap developing wasps in already ...

“Infected fly larvae actively seek out ethanol-containing food, showing they use alcohol as an anti-wasp medicine,” notes...

Parasitized females of several species give their offspring a leg up by preferentially laying eggs on food containing alcohol.

not practiced by uninfected females.

The only other insects currently known to self-medicate are honeybees and a handful of butterflies and moths.

The phenomenon is more widespread in vertebrate animals, enough so for it to have been given its own name: zoopharmacognosy—from the Greek words zoon, “animal,” pharmakon, “drug,” and gnosis, “knowledge.”

adult flies, when threatened by wasps, send warning messages to other flies with rapid wing movements.

The fruit flies fear the wasps so much that when they spot one, they cut future losses by laying fewer eggs. Even flies who have never encountered a wasp before lay fewer eggs on hearing their comrades’ warning whines.

flies learn to recognize the warning dialects of their neighbor species. “The dialect barrier can be alleviated through socialization between species, without which, information would otherwise be lost in translation,” says study author Balint Kacsoh.

Many if not most of these mimics don’t settle for looking like any old bee or wasp. There are flies that mimic yellowjackets, bald-faced hornets, potter wasps, and ichneumon wasps

Marshall noted that the fly enhanced the impersonation by doing something beelike but unflylike: dangling its hindlegs in flight.

total skin surface of nearly 12,000 square kilometers (4,600 square miles),* humans

There are about 3,568 described species of mosquito.

The word mosquito derives from the Spanish for “little fly.”

Mosquitoes also have drought-resistant eggs, which they prefer to lay on soil that still bears the smell of larvae from previous generations. That smell can last for years, allowing viable eggs to accumulate during dry years, then hatch all at once in a wet year.

mosquitoes appear to be more attracted to men. There is also evidence that mosquitoes are attracted to dark clothing, movement, sweat, and beer drinkers.

Only female mosquitoes have the mouthparts for sucking blood, which they use more as a source of protein for their eggs than for personal nourishment. Males seek nectar and other plant sugars, with which some females may also supplement their diets. Male mosquitoes of a few species do approach humans or other warm-blooded animals, but not to feed on them; they are awaiting the arrival of hungry females to mate with. Otherwise males of most species swarm.

most of us become less reactive to mosquito saliva as the biting season progresses. This is an immunological response: more exposed, less reaction.

The itch felt after a mosquito bite is due to salivary proteins left at the crime scene.

The serious mosquito-borne diseases are those that have evolved special ways to avoid the mosquito digestive tract and colonize the salivary glands, from where they can be transmitted through the bite.

They are also aided by their subtle, anesthetic touch, as vouched for by the Canadian novelist Margaret Atwood, who spent formative stretches of her early years in the wilderness of northern Quebec and northern Ontario, where her entomologist father was posted: “In the woods, you wore pants not because it was butch but because if you didn’t wear pants and tuck [them] into your socks you would get blackflies up your legs. They make little holes in you, into which they inject an anticoagulant. You don’t feel them when they are doing it, and then you take your clothes off and find out you are covered in blood.”

On the bright side for northerners, temperate biting midges do not transmit diseases, unlike their tropical cousins.

blackflies live in water before emerging as flying adults. Larvae living in flowing streams use hooks to cling to pads of silk that they plaster onto rocks.

Art Borkent

He was catching and rearing midge larvae by age thirteen, and he says this interest contributed to some false starts with potential girlfriends.

There are currently 113 described species of frog-biting midges (up from 97 when I began researching this book) and, based on limited sampling effort and novelty rates, at least another 500 as yet undiscovered species.