What exactly are armyworms?
The menace known as the “African armyworm” is in fact a caterpillar. It gets its moniker from its habit of “marching” in large numbers into crop fields. During the rainy season, the insects emerge in sudden swarms, devour crops, and then move on once fields are barren. They are the larvae of nocturnal moths, of the species Spodoptera exempta. The moths are capable of long-distance migration – more than 100km (60 miles) per night – allowing the swarms to spread rapidly. Each female lays between 500 and 1,000 eggs in her 10-day lifetime. Once hatched, the larvae migrate through grasslands in snake-like colonies. On reaching crop fields, they begin feasting. At full size (5cm – 2in) the caterpillars can lay waste to whole farms within days. So how do the caterpillars in Liberia differ from armyworms? There are several key differences, according to Tim Vaessen, a UN Food and Agriculture Organisation emergency co-ordinator. While armyworms feed on ground cereal like millet, rice or sorghum,
