locust

Swarming grasshopper with short feelers, or antennae, and hearing organs on the abdomen (rear segment of the body). As winged adults, flying in swarms, locusts may be carried by the wind hundreds of miles from their breeding grounds; on landing they devour all vegetation. Locusts occur in nearly every continent. (Family Acrididae, order Orthoptera.)

The migratory locust (Locusta migratoria) ranges from Europe to China, and even small swarms may cover several square miles, and weigh thousands of tons. Control by spreading poisoned food among the bands is very effective, but it is cheapest to spray concentrated insecticide solutions from aircraft over the insects or the vegetation on which they feed. They eat the equivalent of their own weight in a day, and, flying at night with the wind, may cover some 500 km/300 mi. The largest known swarm covered 1,036 sq km/400 sq mi, comprising approximately 40 billion insects.

A biological pesticide to control locusts was being trialled across Africa by a multinational team in 1997. Dried fungal spores sprayed in breeding areas pierce the locust exoskeleton on germination and invade the body cavity causing death. They fungus is passed from insect to insect and persists in the area making repeated treatment (necessary for chemical pesticide) unnecessary.