Face it: Termites are roaches

Termites are just cockroaches with a fancy social life, according to the biggest DNA study yet of the two groups.

The idea’s been “simmering,” says Paul Eggleton of the Natural History Museum in London. To perform a definitive test, he and his colleagues assembled a set of specimens including 107 species of termites, roaches, and the closely related mantids. Analysis of five DNA sequences that appear, with variations, in all the insects revealed their evolutionary relationships, which the researchers describe in the June 7 Biology Letters.

“We have to face the fact that termites are cockroaches,” says Eggleton. His sober tone comes from expecting resistance to changing the classification of termites, which currently boast their own insect order. They would become instead a family in the roach order, Eggleton says. He studies termite ecology and will feel the pain himself. “I’m guilty of killing my own order,” he says.

The upside, he says, comes from refining insect classifications to reflect evolutionary relationships.

For example, Eggleton says, the new classification shows termites closely related to wood-eating roaches. He proposes that the highly developed social life of termites got its start when ancient roaches began sharing specialized gut protozoa that digest wood.

Susan Milius is the life sciences writer, covering organismal biology and evolution, and has a special passion for plants, fungi and invertebrates. She studied biology and English literature.