Storming of the Locusts

You’ve seen the funny little grasshopper.  He has big eyes, long feelers called antennae, and legs that are kind of bent backwards allowing him to jump fairly long distances; a one-inch grasshopper can leap 20 inches (50.8 centimeters).  That would be like you, a five-foot tall person, say, being able to spring over the length of an entire basketball court! Our leaping wonder belongs to the orthoptera (awr THAHP tuhr uh) family along with Katydids, crickets and locust.  But our story today is about an animal of mass destruction: Locusts. And grasshoppers should not be mistaken for Locust—their behavior sets them apart.

The Rocky Mountain Horror Show

The pioneers saw what they thought was a black storm cloud forming and then they heard a roar that sounded like a fire, they thought: maybe a prairie fire.  But what they realized was a terror far worse than either of the things they’d imagined. The year was 1875, and three trillion locusts were descending from the skies all the way from Texas to Montana.  In the history of the world, this was the largest swarm of record. The weight of the locusts broke the branches off trees. People went screaming to their homes because insects were chewing the clothes off their backs!

The devastation of this horde, which was 110 miles (177 km) wide and 1,800 miles (2,900 km) long, was that they ate every green plant, flower and insect imaginable.  Plants such as clover, corn, cotton, soybeans and other farm crops fell victim—and grains—locust love grains. And then, a few years later, they vanished. Scientists puzzled over this disappearance for 125 years.  Turns out, the locusts had used the river valleys for breeding and the farmers, unknowingly, destroyed the species by plowing up their breeding grounds.

Locusts in Ancient Times

If you know your Bible lore you might remember reading about locust plagues?  The Egyptian people once thought that God sent the locust swarm to punish them, because the people went hungry after the locusts ate all the crops, plus, their stored food supplies.  One writer in Ancient Greece talked about a swarm that “blocked the light of the sun.”

Zero in On Today

Currently a plague (another word for swarm) of locusts are tearing across East Africa right now, as hundreds of billions of insects are laying waste to crops—it’s called the worst Ethiopian outbreak in 25 years and for those in Kenya—the worst in seven decades. 

How much do they eat?  A locust can eat as much as it weighs daily.  But there may be trillions and a swarm as big as that can eat 400 million pounds (182 million kg), in a single day.

The vegetation in these areas have met with unusually heavy rains, and that moist environment and subsequent weather-jumpstart for growing plants provides fodder for rapidly breeding insects.  The UN Food and Agricultural Organization (FAO) is calling the situation “extremely alarming” for the Horn of Africa—the countries of Djibouti, Eritrea, Ethiopia, and Somalia.  It will leave many people with food shortages.

Gregarious Phase

Of the 7,000 types of grasshoppers, there are about twenty species that like to crowd together and their numbers increase; scientists call this the “gregarious phase.”  Not only do their numbers grow exponentially, but their wings and bodies grow bigger and some even change color. They also breed faster and fly more. The ones doing the damage now are: Schistocerca gregaria, a desert locust.  Typically, the desert locust is beige or even a bright green-blue color when it is alone.  When it gathers into swarms however, the head becomes black and orange, the belly turns yellow, and the back gets spotted with a black and white stripe along its side.  No hiding here, there is strength in numbers.

The females breed by drilling a hole in the sand or soil with a body part called the ovipositor (oh vuh PAHZ uh tuhr).  Generally, during the gregarious period, they lay a pod of 30 or more eggs and cover it with a kind of liquid foam that provides protection.  And many females lay eggs in moist soil and in the same area.  The ones that hatch are called “nymphs.”  Bad news on the birth of the nymph: they have huge appetites and eat more than adult grasshoppers.  And there can be a thousand in a square meter of soil.  Soon, they will migrate or travel long distances to find still more food.

Environmental Conditions

Warmer seas spawn cyclones—especially sequential ones that give locusts the wet soils they need to breed as they march across the landscape.  Hurricanes, cyclones and typhoons are all types of tropical storms but what’s the difference between them? They are the same, but called different names depending on where they form: hurricanes are tropical storms that form over the North Atlantic Ocean and Northeast Pacific; cyclones are formed over the South Pacific and Indian Ocean; and typhoons in the Northwest Pacific Ocean.  Guess what? on a warming planet, locust win.

But if the people who live near the breeding areas can be notified, and their countries emergency factions notified about possible outbreaks sooner, (by the FAO,) they can control the locust with pesticides.  And, yes, the chemicals are harmful to nature and people as well, but there is hope for a new biocontrol method—a killer fungus called Metarhizium acridum, which only torments locusts and grasshoppers.  That would be good.

References:

Brennan, Patricia. Grasshoppers and Their Relatives. Chicago: World Book, Inc., 2012. Book.

Hillman, Ben. How Weird is It? A Freaky Book All About Strangeness. New York: Scholastic Inc., 2009. Book.

McAneney, Caitlin. Animals of Mass Destruction: Locusts. New York: Gareth Stevens Publishing, 2015. Book.
Locust Watch
National Geographic: Locusts

Simon, Matt. Wired. “The Terrifying Science Behind the Locust Plagues of Africa”<br> Feature photo - pixabay.com