In 1996, many swarms of red locust, Nomadacris septemfasciata (Serville), formed in the Buzi-Gorongosa outbreak area in Mozambique. Some of these swarms migrated and crossed international boundaries, on a scale not seen since the last plague of 1929–1944.
The swarms did not breed in countries that they invaded, namely, Zimbabwe, Zambia, Botswana and South Africa. On the other hand, in Malawi, successful breeding by the swarms resulted in hopper bands. Filial generation outbreaks continued into 1997 in the breeding area, but at a reduced scale.
An analysis is made of the possible causes of the upsurges of 1996 and the likely implications to the preventive control strategy that has been the principle for red locust plague prevention.
There is need for a further comprehensive study of the Buzi-Gorongosa plains so as to understand better the factors that contribute to its high potential as an outbreak area.