BOB HIRSHON (host):
How locusts conquered the world. I’m Bob Hirshon and this is Science Update.
Desert locusts have plagued humans since the dawn of agriculture. Now evolutionary biologists at the University of Toronto have found that some 4 million years ago the pests likely made an epic Atlantic crossing as they migrated from Africa to the Americas. All American desert locust species seem to be descended from this one swarm. Nathan Lovejoy says how they did it is a mystery.
NATHAN LOVEJOY (University of Toronto):
People have studied these locusts in wind tunnels, for example, and they don’t seem to have enough energy to fly all the way across the Atlantic.
One hypothesis is that dead locusts formed floating mats on the water where the others could rest and eat. Surprisingly, in 1988 another swarm made the trip, riding a storm system all the way to the Caribbean.
I’m Bob Hirshon, for AAAS, the science society.