Sampling Problems with Tsetse Flies (Diptera: Glossinidae)

(1) Studies were made of Glossina morsitans morsitans Westw. and G. pallidipes Aust. captured from (a) stationary sources of ox odour (electric trapping); (b) natural refuges and branch resting places (hand-net catching); (c) artificial refuges (curtain trapping): (d) a mobile ox (hand-net); and (e) mobile screens (electric and hand-net). (2) Temperature, time of day, type of refuge, and site affected the magnitude or composition of some of the catches, but generally the odour sources and refuges gave samples which roughly represented the sex and species composition of the wild populations, whereas mobile baits gave catches with low proportions of females and relatively few G. pallidipes. (3) Refuges collected samples with a wide range of nutritional states, but electrocuting grids used in conjunction with odour sources caught samples which were in a late stage of the hunger cycle. All mobile baits collected few flies which had fed recently, but the balance between flies in intermediate, late and very late stages of the hunger cycle varied according to bait or catching method. (4) The convenience of odour-baited traps and their ability to produce large samples with representative sex and species composition indicated their value for ecological studies.