Fungus-farming insects: Multiple origins and diverse evolutionary histories

摘要

About 40-60 million years before the advent of human agriculture, three insect lineages, termites, ants, and beetles, independently evolved the ability to grow fungi for food. Like humans, the insect farmers became dependent on cultivated crops for food and developed task-partitioned societies cooperating in gigantic agricultural enterprises. Agricultural life ultimately enabled all of these insect farmers to rise to major ecological importance. Indeed, the fungus-growing termites of the Old World, the fungus-growing ants of the New World, and the cosmopolitan, fungus-growing beetles are not only dominant players in natural ecosystems, but they are also major agriculture, forestry, and household pests (1). Not surprising, much is known about the extermination of these pest insects, but only recently have genetic techniques been applied to elucidate the evolutionary histories of these unique nonhuman agricultural systems.