We all know climate change leads to more hurricanes, longer droughts, colder winters and rising sea levels. But did you know it also causes caterpillar invasions?

Well, that's the latest theory on why the African countries of Liberia and Guinea are currently overrun with Achaea catocaloides - millions of black, hairy caterpillars about one inch (2-3 cm) long. At first, they were thought to be the similar looking "army worm", but the species has just been identified. 

How bad can a caterpillar invasion be? Very. These caterpillars have not only eaten all of the crops and get into the houses, they've also gotten into the water supply and caused an estimated 500,000 Liberians to flee their homes.

It's not just their bodies that have polluted the water - it's their excrement. Officials are now worried that the hungry, hairy hoard will head for Sierra Leone and other African nations after they are through devouring Guinea. Apparently, Liberia was just an appetizer.

What The Climate Has To Do With Caterpillars

In the last few years, Liberia's rainy season has been getting longer and longer.  This has led to more desirable conditions for any caterpillar eggs to hatch.  Usually, some caterpillar eggs die before they can hatch.  Now, it seems every egg is a winner.  And with a longer rainy season, more vegetation grows and there's more to munch.  But, if they hatch when it's cooler in the forests, they march south to farmlands.

With the longer rainy season, the temperatures have been colder in the forests, so the caterpillars have been eating cocoa, coffee and crops for livestock.

Habitat destruction has also been steadily killing off the caterpillar's predators, including frogs and birds.  The usual farm pesticides don't reach the caterpillar eggs, because the moths breed in what's left of the wild forests.  Also, they breed high up the canopy, far from the usual ground-settling pesticides. 

Many caterpillars are also able to burrow far underground, far past where the usual pesticides reach, to make cocoons and change into moths.  This means that over the last few years, more adults have been surviving to breed and lay eggs.  Females lay up to 1,000 eggs.

Army worm caterpillars don't crawl very fast.  They travel mostly by air.  The wind is strong enough to lift up millions of caterpillars and take them to new places to eat.

What To Do?

Liberia has declared a state of emergency.  Pesticide use in Liberia has been considered, but it could poison any groundwater.  Guinea is using aerial pesticides anyway, despite the dangers of soil and water contamination, spraying pesticide along the Liberian-Guinea border.

The UN is trying to raise money to house and feed the thousands of climate change refugees. 

So far, there really is nothing these people can do except suffer until global climate change is taken seriously enough so that weather patterns can get back to normal.  Let's just hope they don't try and bring in Cane toads. 

Related Reading:
Climate Change Displacement: Leaving Home for Nowhere
Warming Oceans Changing SE Asia Monsoons

Image Credit:
www.dlcoea.org.et