How much damage can a swarm of locusts do?

A swarm of locusts attacking vegetation.

A huge swarm of desert locusts can turn acres upon acres of growing crops into a sorrowful sight, giving rise to famine conditions.

A single locust will eat the equivalent of its own weight each day.

When we consider that a large swarm may consist of billions of locusts, the amount of vegetation consumed is colossal.

An estimated 40 billion locusts in a swarm covering some 400 square miles (1,036 square kilometers) may devour some 80,000 tons of food daily!

Attack of a swarm of locusts

The sound of an approaching locust swarm may be heard for a distance of about six miles (10 kilometers).

Like a well-organized fighting force the locust army advances, reducing all vegetation in its path to a state of ruin.

Also, linen, wool, silk and leather do not escape the locusts’ jaws.

When invading houses, they do not spare even the varnish on the furniture.

In desperation, farmers may throw rocks and cans and hit at the locusts with reeds and sticks. But in the end, everything is in vain.

The locusts are just too many.

The onslaught continues. So great are their numbers that they appear as a cloud or blizzard darkening the sky.

Happily, it is not every year that desert locusts invade in full force, wreaking awesome devastation.

Why is this?

Weather conditions are primarily responsible.

During dry years, when vegetation is limited in desert areas, locusts do not hatch in great numbers and thereafter do not group together.

They resemble green grasshoppers.

But when there are repeated rains in the deserts, locusts hatch in tremendous numbers and become gregarious.

Their color changes from green to yellow, black and red.

The change in behavior and color results from the locusts’ touching one another.

This has been confirmed by scientific experiments.

Confined to a jar wherein the touching effect is simulated by small swirling threads, a desert locust gradually undergoes a color change.

Modern methods of controlling locusts, particularly by aerial spraying, have limited the extent of locust plagues.

But they do not stop locusts from reproducing in great numbers.

The only thing that can really prevent a locust plague is a natural disaster—drought.