Humans (myself included) like to think of ourselves as the most important species on our planet, but we are sorely wrong. If we all ceased to be, the world and nearly all of its species would survive—and probably thrive. But the so-called eusocial insects, bees, ants, and termites, fill such important ecological niches that were they to disappear, so too would most of the life on the Earth. Bees are the most prolific pollinators in most of the world’s biomes, while ants and termites both play vital roles in maintaining soil health and decomposing dead plant matter.
The termites are the most ancient social insects and first evolved around 145 million years ago. The first termites were really ancient cockroaches that hosted cellulose-digesting bacteria in their guts. Since then, thousands of new species developed; there are over 2,600 today. Termites flourished almost immediately because they were capable of digesting wood fibers, or cellulose, as few other land animals could. This symbiosis proved particularly successful, and once termites had evolved that capability, they never looked back. In today’s tropical rain forests, as they have for over 100 million years, they are the primary decomposers, consuming almost all of the dead wood and plant material.
Their success can be measured in the millions of tons; termites comprise as much as 10% of the total biomass of all the world’s land animals. The only insects more massive and numerous than the termites are the ants, their mortal enemy. To protect their colonies, the termites evolved a caste of soldiers with highly specialized weapons. Some termite soldiers can spray toxins from their foreheads, others use enormous jaws to destroy invaders, while other have heads so large that they block tunnels and prevent ant invasions.
Soldier termites, like most of the millions in a large colony, are completely sterile. They exist only to protect the colony and are fed by the much more numerous workers. Both of these termite castes work their entire lives to ensure the reproductive success of their queen (or queens), around which the entire colony is built. Termite queens live for as long as 50 years, and become more fertile each year. A mature termite queen’s body is mostly reproductive organs, allowing her to lay one egg every ten to fifteen seconds. In addition to turning out new workers and soldiers, she produces winged immature queens (called alates) that fly from the colony in tremendous numbers. The alates have a survival strategy based on predator satiation; in other words, so many of them are produced that predators can not possibly eat them all. Those few that survive may then form new colonies of their own, producing millions of offspring throughout their long lives.
The impact of the tremendous numbers of termites is not local, or even regional, but global. Termites are the cows of the insect world. Their methane flatulence, combined with their staggering numbers, has a remarkable effect on the global climate. Methane emissions from the guts of termites are responsible for approximately 4% of the worldwide total. If not for the massive proliferation of cows, sheep, and other ruminants intended for human consumption, termites would be the main animal source of methane in our atmosphere. Termites have also been implicated in the evolution of modern angiosperm trees, as well as the development of red-tropical clays that may require the extreme alkaline conditions in the termite gut to form. The world would be a very different place without them.
Termites are the premier architects of the natural world. Certain species build large mounds that can reach up to 20 feet in height. These mounds serve to protect the colony from predators and floods, provide a large thermal mass to keep the queens at a comfortable temperature, and to dispose of wastes. The mounds are actually made up largely of saliva-cemented feces that has been digested not once, but several times. Because of the low efficiency of wood digestion, termites consume their wastes repeatedly in order to remove as much of the nutritional value as possible. The fully processed waste then provides a hard, decay-resistant building material.
Their predilection for mound building has an interesting side-benefit for humans; termites are fantastic gold prospectors. The excavated material for these mounds can come from several hundred feet below and thousands of feet away. Because they dig so deeply, termites can access the relatively unmodified rock and soil from which the thick tropical red clays develop. This parent material has not yet been exposed to the hard rains that wash out most minerals, including gold. Some termite mounds can be so rich in gold that dissolving them and panning the slurry provides a significant side income for poorer residents of tropical regions.
But the economic benefits of gold discovery are nothing compared to the billions spent around the globe each year in termite damage prevention. There are two groups of termites: those that live and die exclusively within a single woody mass, and the subterranean variety that lives in the ground and can seek out new sources of food. This second type is far more damaging to human construction because they move and live below ground, and eat a structure literally from the inside out, making them hard to detect. The historic Garden District and French Quarter in New Orleans survived Hurricane Katrina, but they may have a harder time standing against the voracious subterranean Formosan termite.