Odour-baited targets as invasion barriers for tsetse flies (Diptera : Glossinidae): a field trial in Zimbabwe

In Zimbabwe, odour-baited targets impregnated with deltamethrin were deploy ed at 4 km(-2) in a 9 km-wide band as an invasion barrier against dense pop ulations of Glossina morsitans morsitans Westwood and G, pallidipes Austen. Tsetse populations across the barrier were monitored by a line of traps. I nvasion pressure was estimated by the catches from two additional traps abo ut 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, i ndicating that the barrier was effective in preventing re-invasion, and tha t the 9 km-wide barrier gave a good margin of safety.