The Anglo-Egyptian Sudan has, so far as may be ascertained, always been liable to plagues of the migratory locust, Schistocerca gregaria, Forsk., generally referred to as the desert locust. In the summer of 1930 in addition to this species swarms of another migratory locust, Locusta migratorioides, Rch. & Frm., locally known as the hairy-chested locust, appeared. In most districts natives stated that they had never before seen this second species, but elderly inhabitants of Darfur and northern Kordofan recognised it as having occurred some forty-two years previously for two successive seasons; the first year in large numbers, the second in but small numbers. It was hoped that history would repeat itself and that the hairy-chested locust would be relatively scarce in its second year, but unfortunately this hope has not been realised; L. migratorioides was a more serious plague in 1931 than in the preceding year.