Continuous trapping of winged Aphids was carried out with Moericke trays and a suction trap for two years at a site at 6,850 ft. above sea level in Kenya, and with Moericke trays, for four months only, at a site at 1,200 ft. in southern Tanganyika.
The trap data show a marked seasonal periodicity of flight (three-quarters of the annual catch in two months) at the Kenya site. The large catch is a reflection of a large increase in population following the rains. A similar relation between size of catch and the period of the rains is indicated by the data from Tanganyika.
Successive hourly catches with a suction trap show no distinct diurnal double peak of aerial density such as occurs in Europe.