The choppers swoop in, dumping insecticide over a plague-stricken village in Madagascar's stunning central highlands. "The goal is to break the invasion," explains Tsitohaina Andriamaroahina, head of a U.N. mission to end a locust plague threatening the crops of 13 million farmers on this island nation. n their countless billions the insatiable hordes cloud the skies as they spread across two thirds of Madagascar, affecting an area roughly the size of Germany or Japan.