oa East African Geographical Review - East African record locusts in East Africa and the nature of the current threat

Abstract

Locusts have figured in records from the earliest times as one of the most dramatic of insect pests. Not until Uvarov propounded his phase theory in 1921 was progress made in understanding what locusts are and how they appear so suddenly and with devastating effect. Uvarov showed that locusts were simply grasshoppers (Acrididae : Orthoptera) with the special facility of changing phase from the normal solitary form to an active gregarious form. This led to extensive field exploration in the 1930's and 1940's which gave an understanding of the outlines of the process in Africa and to the setting up of control and research organisations.