Way of the Locust

Scott LaFee
Thu, 22 Jan 2009 00:00:00 -0800
Lifestyle

Most of the time, the life of a locust is a solitary and cryptic existence. Then, every so often, the bugs gather in swarms comprised of thousands, perhaps millions, of individuals — a massive munching machine capable of stripping fields and croplands bare.

Scientists have never been able to explain the transformation satisfactorily. Indeed, the insect changes not just behavior but also physiology, color and shape.

An explanation may finally be at hand. In a paper published in Current Biology, Andy Reynolds of Rothamsted Research in England says that when locusts' numbers grow to a certain threshold, the insects come together to foil predators.
Updated: Wed Jan 21, 2009

Most of the time, the life of a locust is a solitary and cryptic existence. Then, every so often, the bugs gather in swarms comprised of thousands, perhaps millions, of individuals — a massive munching machine capable of stripping fields and croplands bare.

Scientists have never been able to explain the transformation satisfactorily. Indeed, the insect changes not just behavior but also physiology, color and shape.

An explanation may finally be at hand. In a paper published in Current Biology, Andy Reynolds of Rothamsted Research in England says that when locusts' numbers grow to a certain threshold, the insects come together to foil predators.

When dispersed, individual patches of locusts can be easily picked off, with predators like birds, mammals and other insects moving from one patch to the next. In huge swarms, however, the locusts actually reduce their overall exposure to predators.

In other locust news, American and Canadian researchers say locusts arrived in the New World 3 to 5 million years ago after a massive swarm took off from the west coast of Africa, heading west. It's not clear how the locusts survived the trip, since they don't have enough fat to power a journey of several days.

"One unlikely hypothesis is that while the locusts were flying across, as their brethren died and landed in the ocean, they formed huge floating mats of dead locusts," said Nathan Lovejoy of the University of Toronto. "The other locusts would land on these mats, rest and feed on the dead bodies, then take off and keep flying."

VERBATIM

The laws of nature are but the mathematical thoughts of God.

— Greek mathematician (and the father of geometry) Euclid, circa 300 B.C.

BRAIN SWEAT

Quick, which would you rather have — a half a dozen dozen dimes or a dozen and a half dimes?

BRAIN SWEAT ANSWER

This is a definite case where it's not just six of one and half a dozen of the other. Half a dozen dozen is six dozen or 72 dimes, while a dozen and a half is just 18 dimes. That's a difference of $5.40.

QUIRKS OF NATURE

A horse can identify another horse by its whinny alone.

WHAT IS IT ANSWER

The head of an Aeshna cyanea male dragonfly, which is greatly magnified.

POETRY FOR SCIENTISTS

An android, it's often been said

(A machine with four limbs and a head)

Is designed to survive:

It's not truly "alive,"

Yet it's clearly a long way from dead.

— Chris J. Strolin