Abstract
In Zimbabwe, odour-baited targets impregnated with deltamethrin were deployed at 4 km-2 in a 9 km-wide band as an invasion barrier against dense populations of Glossina morsitans morsitans Westwood and G. pallidipes Austen. Tsetse populations across the barrier were monitored by a line of traps. Invasion pressure was estimated by the catches from two additional traps about 6 km into the invasion source. After 14 months all traps more than 7 km from the invasion source recorded zero catches for 12 consecutive months, indicating that the barrier was effective in preventing re-invasion, and that the 9 km-wide barrier gave a good margin of safety.