Abstract
Two experiments in which G. pallidipes Aust. was caught on oxen, in Morris traps and on a fly-round in south-eastern Uganda are described.Fewer flies were caught in traps than on oxen, but the former took a higher proportion of females. The numbers in traps covered with natural-coloured hessian tended to be greater than in traps on which the hessian was painted black. A white ox attracted fewer flies than darker-coloured oxen, among which a red ox was the most attractive. Variations reflected in day and site effects indicated that the sexes were differentially affected by the factors controlling availability to the oxen and the traps. Fly-round data appeared to give an unsatisfactory estimate of the population density.The numbers caught by the various methods were, in general, not correlated and this casts doubt on the validity of fly-round or trap data as estimates of the number of G. pallidipes likely to attack cattle.

This publication has 17 references indexed in Scilit: