Speaking at the Kaiser Family Foundation, Wilson said if humans vanished, only three species of insect would join them in extinction. Close relatives of body and head lice would continue to live on our primate cousins.

But mass insect extinction could mean no more nematodes and other worms moving soil around, and bees and other pollinators aiding plant reproduction. Agricultural yields would drop, bringing starvation, war and an "ecological dark age."

"The survivors would offer prayers for the return of weeds and bugs," Wilson said.

Beekeepers in the United States already are confronting colony collapse disorder. In about 25 percent of the managed hives in the United States, worker bees are leaving and not coming back -- and no one knows why.

Wilson, a longtime Harvard professor, has won two Pulitzer prizes for his popular science writing.