Putting the science in fiction - Dan Koboldt, Chuck Wendig 2018
What bugs me about insects
From zero to sixty (legs, that is)
By Robinne Weiss
Arthropods (insects, spiders, centipedes, etc.) show up regularly in fiction. I love a good science fiction or fantasy story, but as an entomologist, I often cringe at the way arthropods are portrayed in books and movies. Here are a few of the common portrayals that “bug” me.
Huge arthropods
There’s no doubt that increasing the size of an arthropod to that of a bus makes it a more terrifying antagonist (let’s face it, Shelob in The Lord of the Rings would have been nothing but a nuisance if Frodo could have squashed her with his heel), but unless your giant insects live on some other planet with different physical laws and gravitational conditions, it’s simply not possible.
As an animal increases in size, its surface area increases in proportion to the square of the length of the animal (because surface area is measured in two dimensions), but the animal’s volume increases in proportion to the cube of the length (because volume is measured in three dimensions). So as an arthropod’s size increases, its volume-to-surface ratio goes up. This relationship has important implications for the behavior of a hypothetical giant arthropod.
Ants seem incredibly strong because their muscles are moving a very small mass compared to the muscles’ cross-sectional area. But if we increase the size of an ant to that of a human, the ratio of mass-to-muscle cross-section rises dramatically. So an ant the size of a human would have about the same physical prowess as a human.
Okay, so maybe huge arthropods wouldn’t have superhuman abilities, but they’d still be impressive, right?
Except they couldn’t possibly grow that big in the first place.
Arthropods have an exoskeleton—the rigid structure of their bodies is on the outside. An exoskeleton is great if you’re small because it provides both structure and protection. Unfortunately, an exoskeleton has some major disadvantages at larger sizes.
Exoskeletons don’t grow with the animal’s body. In order to get larger, an arthropod must shed its old exoskeleton and grow a new one. When the old exoskeleton is shed, the new one is soft and pliable. It takes time for the new exoskeleton to harden. That’s fine for a small arthropod because the pull of gravity is not great on a small body. Enlarge an arthropod to the size of a human, however, and it will be crushed by its own weight before its new exoskeleton can harden.
Insects as bad guys
Books and movies love to demonize insects and other arthropods. It’s always the spiders, ants, bees, or whatever that threaten humanity. But the truth of the matter is that we couldn’t survive without insects.
Everybody can name insects that can harm us or our crops. We are familiar with these pests because they seek us out as a source of food. But fewer than 1 percent of insect species are pests, and those that are considered pests are often only a problem in particular times and places, not all the time. Most insects are beneficial or neutral as far as humans are concerned.
Insects provide food for wildlife, control pests, and help break down dead plant and animal material. They are used in scientific research and medicine. They pollinate 35 percent of the world’s crop production. Without them, there would be no coffee, no chocolate, no fruits or vegetables. Insects also provide honey, wax, silk, shellac, and food coloring.
Far from being our worst enemies, arthropods are essential to our existence. I would like to see them appear as the good guys in fiction now and again.
Truth is stranger than fiction
What bothers me most about insects portrayed in fiction is authors often don’t know the facts about insects, so they miss out on a deep well of creative opportunity. The truth about insects can be so outrageous it hardly needs fictionalization. Here are some inspiring true stories of insects that I would love to see worked into fiction.
Chemical Warfare
Insects and other arthropods are masters of chemical defense. Some collect toxins from the plants they eat; others manufacture their own poisonous arsenal. Some inject their toxins with stingers or fangs, but many more exude or spray noxious chemicals from glands on various parts of their bodies. Thousands of species of vinegaroons, cockroaches, earwigs, stick insects, beetles, and other arthropods can eject irritating chemicals with surprising accuracy and range when threatened. Some of these chemicals are the most concentrated acids occurring in nature, and it’s a wonder the insects themselves can tolerate them.
Blister beetles are an extreme example of chemical protection. They contain the chemical cantharidin, which has been considered an aphrodisiac in the past because, when taken orally by men, it causes erections. Unfortunately, it does so by destroying the man’s renal and reproductive systems. Half a dozen blister beetles contain enough cantharidin to kill a person.
An example close to home is the friendly ladybug, beloved by gardeners and school children. But ladybugs’ cheerful appearance is deceiving. Their bright coloration warns predators they are toxic. Their blood is packed with bitter alkaloids. When they are attacked, they bleed from their knee joints, giving the predator a nasty mouthful. Some scientists speculate that poison dart frogs may eat ladybugs, stealing the ladybug poison for their own protection.
Pavlov’s Bees
Most insects are highly sensitive to smell. The chemoreceptors on their antennae can detect chemicals in concentrations much lower than humans can.
Researchers have taken advantage of these abilities. Honey bees and moths have been trained to detect land mines. Parasitic wasps have been trained to sense explosives, illegal drugs, plant diseases, and buried bodies. Researchers train insects by feeding them treats laced with the chemicals until the insects associate the chemicals with food—a bit like Pavlov’s dogs.
Parasitoid Wasps
The most well-known use of parasitoids in science fiction has to be in the Alien movies. Parasitoids lay their eggs inside other organisms. The eggs hatch out, and the baby parasitoids eat their host from the inside out, keeping their host alive by saving the critical organs for last. This type of parasitism is common in the insect world. Some of the most spectacular examples of parasitoids are the giant ichneumon wasps in the genus Megarhyssa. Some species of Megarhyssa have ovipositors (egg-laying tubes) 4 inches (100mm) long. Their ovipositors, stiffened by blood pressure, can drill deep into wood. Sensors on the tip of the ovipositor can taste horntail larvae—the wasps’ prey—that live inside tree trunks.
Aerial Maneuvers
Fantasy and science fiction often involve spectacular flying fantasy creatures—dragons, enormous birds, griffins, and the like. But if you’re looking for feats of aerial agility, insects beat fantasy creatures every time. Insects can steer accurately at speed, hover, and fly sideways or backward. They need no runway, starting and stopping their flight from a standstill. Some predatory insects, like dragonflies, tiger beetles, and robber flies catch other insects on the wing. Many moths can outmaneuver even a hunting bat. Insect flight can seem to defy gravity and physics, and scientists are still trying to work out exactly how insects manage what they do in the air.
Biblical Plagues
Plagues of locusts appear occasionally in fiction, but the astonishing biology and ecology of locust plagues is rarely seen.
Plague-forming locusts generally live in arid regions where food is sparse. Most of the time, locusts are solitary. They’re well camouflaged by their green or brown color, and they actively avoid other locusts. Locust numbers rise rapidly during periods of wet weather. When it dries out again and food becomes scarce, the locusts are forced to congregate in the remaining patches of food. When this happens, they undergo a tremendous shift. The parts of their brains associated with learning and processing complex information grow. Their bodies turn from cryptic greens and browns to bright orange and black. They switch from a purely vegetarian diet to a diet that includes cannibalism. Their flight muscles grow. They actively seek out other locusts and start moving in huge numbers across the landscape. They essentially transform into an entirely different insect, all in the course of a few weeks.
Entomological Warfare
Arthropod-borne diseases such as malaria, yellow fever, encephalitis, and dozens more kill millions of people every year. It’s no surprise that military powers have tried to put these diseases to work during wartime. The most developed of these endeavors took place in Japan during World War II. Using Chinese prisoners as guinea pigs and blood sources, the Japanese military weaponized plague-infested fleas and cholera-infected flies, releasing them in China and killing tens of thousands of people. The program was effectively hushed up by the U.S. military after the war in a rather morally suspect deal in which the Japanese mastermind behind the entomological warfare program, General Ishii Shiro, was given immunity from prosecution in exchange for his data.
If I were to give advice to authors writing insects into their stories, it would be to get to know the real-life versions of your many-legged characters—they may not be who you think they are, and they may be much more interesting.