Of the world's most dangerous migratory pests, locusts probably top the list. Locust infestations are at their worst levels in nearly a quarter of a century, an environmental blight that threatens the food supplies and livelihoods of millions. Hundreds of billions of locusts are currently swarming through parts of East Africa and South Asia, highlighting the food and water vulnerabilities of both regions.
The dangers, however, are not limited to crops; in January last year, locust swarms were dense enough to force an Ethiopian Airlines plane off its course. A joint statement by the World Food Programme (WFP) and Food and Agriculture Organisation (FAO) noted that the scourge has been of “biblical proportions”, with its scale "unprecedented in modern times”. In regions rife with poverty, what can be done to combat this menacing infestation?
What is a locust?
A locust plague is a devastating natural disaster. These infestations have been feared throughout history and still wreak havoc today. Locusts (Schistocerca gregaria) are related to grasshoppers, and the two insects look very similar. Ordinarily, locusts are harmless, solitary insects; however, when many gather together, their behavioural instincts can change. This is known as the gregarious behavioural phase; locusts begin to breed and ravenously consume vegetation, especially stable cereal crops, legumes and pastures.
For instance, an average swarm can contain up to 40 million insects, travel up to 150 km in a single day, and devour food which would normally feed millions within a very short period of time. Indeed, the destructive insect can eat its own weight in food. Among several species of locusts found around the globe, the Desert Locust is considered the most dangerous as it can migrate over vast distances and rapidly breed. This species of locust is usually restricted to the semi-arid and arid deserts of Africa, the Near East and South-West Asia, areas that receive a small amount (less than 200mm) of rain annually.