Consider This

SUNDAYREVIEW | OPINION
Bug Love
By SCOTT R. SHAW
AUG. 23, 2014

LARAMIE, Wyo. — IT’S summertime, the season of insects, and if you spend any time outdoors (or even indoors), you’ve probably been swatting and stomping your way toward fall. Mosquitoes and midges dance over ponds, butterflies and bumblebees tussle on daisies, crickets and katydids trill melodies, moths zigzag around lights leaving dusty trails.

Pests all, you might assume of these six-legged creatures. And hundreds of them are just that — pests. Mosquitoes and lice suck our blood and spread diseases, armies of caterpillars eat our crops, flies divebomb us, termites eat our homes, roaches invade our kitchens.

But of the millions of insects, only a tiny fraction of them, less than 1 percent, are pests. A vast majority are beneficial to humans: They are pollinators, seed dispersers, nutrient recyclers, soil producers and predators or parasites of plant-feeding insects. They are food for frogs, salamanders, lizards, snakes and especially birds. Some are important indicators of water quality. Bugs contain an astronomical array of chemical compounds, some exploited commercially, such as beeswax and cochineal dye. And they are sources of medicines, oils, waxes, fibers, dyes and scents.

In North America, 87,000 insect species have been identified. Most are microscopic and mysterious. The tiniest, fairy fly wasps, are too Lilliputian to see; they’re so small that several can have a dance party on the head of a pin. You might actually inhale and exhale a fairy fly, just as you might a dust speck. 

Many await discovery. Here in Wyoming, I’ve found new species hovering over ant mounds, flying around my porch light and inside my old minivan. When you sneeze, you may expel an unnamed creature.

Insects are the products of threebillion years of evolution. They may seem alien, full of greenish goo, but they are complex creatures with intricate organs and elegant sensory systems: multifaceted eyes, ornate antennas, and pits, pegs and pores across their cuticles.

Their small sizes have promoted species diversity by allowing them to divide the world into extremely small niches. For as long as 150 million years, insects were the only animals that could fly, allowing them to colonize new places. They have also evolved elaborate methods of development, including complex metamorphosis, which has allowed adults to avoid competing for food with their larval offspring.

They may be tiny, but they’re tough. They have adapted to some of the most extreme conditions on the planet. And try as we might, over the last century, we have not managed to extinguish even one pest species. The malaria mosquito, housefly, human-body louse and hundreds of others have developed resistance to insecticides. These poisons have also stimulated the production of new secondary pests (by killing beneficial predators), as well as posing threats to wildlife and humans.

Still, the rampant destruction of tropical forests is driving to extinction insect species that are mostly unknown to us. Vanishing with them are their hidden secrets, mysterious behaviors and unique chemicals. We’re wiping out potentially beneficial species that can never be replaced.

Since the pests we encounter are often highly adaptable and seemingly indestructible, it is tempting to assume that all insects possess those qualities. That’s not the case; many of them, such as bees, butterflies and dragonflies, can be easily harmed by our incursions on their habitats. The collapse of bee populations in recent years, for instance, has been associated by some scientists with pesticides.

Of course, the one species that seems immune to our best efforts at eradication is the American cockroach. Despite its name, it is an invasive species, having arrived here from Africa at least as early as 1625. In the forests of Africa, or even in Central Park, they’re beneficial, as scavengers, recyclers and food for other wildlife. But when they move into our homes, they become pests.

The point being, what might be a pest in one context may not be in another. I enjoy seeing Cabbage White butterflies visiting flowers in my yard, but when their caterpillars riddle my broccoli, they become pests.

The popular assumption is that cockroaches can survive anything, including nuclear explosions. You may have heard the joke: After the nuclear apocalypse, all that will remain will be cockroaches and Keith Richards. There’s a bit of truth to that, at least about the cockroach. They’re more tolerant of radiation than humans, and since they exist all around the planet, it seems probable some will persevere if we humans destroy ourselves.

So consider this: The next time an insect crawls across your path, master your impulse to squash it immediately and instead kneel down to observe its microscopic majesty. You’re seeing a creature whose buggy ancestors survived asteroids, volcanoes, continental drift, climate fluctuations and glaciers. Admire it, respect it. And rest assured that most insects will survive, while we are just a brief phase on this planet of bugs.

Scott R. Shaw is a professor of entomology at the University of Wyoming, where he is curator of the Insect Museum, and the author of “Planet of the Bugs: Evolution and the Rise of Insects.”

A version of this op-ed appears in print on August 24, 2014, on page SR6 of the New York edition with the headline: Bug Love.