Beneficial Insects. The Future

Not all insects, though, are pests, despite widespread human squeamishness about creepy-crawly "nasties" and the virtually medieval association of "bugs" with dirt and uncleanliness. It has been, after all, more than a century and a quarter since the French scientist Louis Pasteur (1822-1895) disproved the notion of "spontaneous generation" of animalcules from decaying organic matter.

Certain insects today are imbued with positive characteristics rather than the usual "yuck" factor. This increasingly positive feeling toward insects as a valuable part of the natural world has great significance for the future of humankind's relationship with the environment.

Honeybees are widely appreciated for their sweet harvest, and bumblebees, even though (contrary to popular opinion) they don't provide honey, are adored for their cuddliness and respected for their earnest hard work. Butterflies are applauded for their bright natural beauty, and although moths are generally viewed with suspicion for their nocturnal haunts, some of them give us silk, a byword for luxury and wealth.

Ladybirds (ladybugs) are the bright subjects of children's rhymes and popular good-luck chants, and fireflies are miraculous glowing wonders of the mysterious natural world. Even some large and rather ominous-looking creatures are revered: dragonflies for their voracious mosquito-hawk prowess and crickets for their shrill but pleasing song.

Today insects are used as biological control agents—parasitoids and predators against crop pests and key herbivores against invasive alien weeds. They are used as indicators of environmental quality, measuring pollution of freshwater and the ecology of ancient forests.

The monarch butterfly (Danaus plexippus) is an eco-tourist attraction at its mass overwintering sites in Central America. Silk and honey are still major industries. These relatively concrete uses aside, insects are now exerting a more subtle and abstract pressure on human understanding of the environment. They provide a window into the realization that the world is a wondrous and awe-inspiring place.

The Future. Across most of the globe today, humankind's relationship with the environment is a socioeconomic one, based on sovereign ownership of the land, commercial use of the land, and its financial productivity. But reemerging in the psyche of a relatively educated and wealthy Western population is an awareness of the conflict between unsustainable human activities and the perceived view of wilderness, nature, and life on Earth. The sheer number of insects is bringing an intellectual and moral weight to bear on the wider protection of the environment.

The British scientist J. B. S. Haldane (1892-1964) was reputedly asked by "some solemn ass" what could be inferred of the work of the Creator from a study of the works of creation. "An inordinate fondness for beetles" was his crushing reply.

To some, his reply might at first seem facetious, but such is the magnitude of insect number and insect (especially beetle) variety that scientists are still debating the complex issues. One of these issues—the almost unimaginable diversity of the Earth—is becoming increasingly important in humankind's relationship with the world, particularly in an age of Earth summits and biodiversity initiatives.

At the end of the twentieth century the measure of insect diversity (the number of species in the world) was based on the number of known species housed in the world's museums and on the descriptions of those species that had been published in the scientific literature. By 1980 about 1.2 million animal species were known, 1 million of these being insects. But when entomologists (those who study insects) began to study tropical rain forest trees, this number had to be dramatically increased.

The technique of counting was simple—an insecticide fogging machine, hauled up into the rain forest canopy, knocked down huge numbers of insects (especially beetles) previously unknown to science. Extrapolating the data led to the suggestion that there are perhaps 30 million tropical arthropod species.

Other researchers have followed this lead and have reinterpreted the data. But instead of consensus arising, further confusion rules. Current estimates of insect diversity lie somewhere between 3 and 85 million species. Whatever the number, fears are that most of them will become extinct from humanity's unsustainable use of the land before they are ever found or described.