The responses of Glossina pallidipes and G. longipennis (Diptera: Glossinidae) to odour-baited traps and targets at Galana Ranch, south-eastern Kenya

Abstract

AbstractFour designs of trap, all made from identical material, were compared at Galana Ranch, south-eastern Kenya, as sampling devices for Glossina pallidipes Austen and G. longipennis Corti. The NG2G and Epsilon traps caught more than twice as many female G. pallidipes as the biconical trap, and the F3 was intermediate. A similar, pattern was observed for males, although the differences were smaller, and not significant. The NG2G, Epsilon and F3 traps all caught approximately twice as many male and female G. longipennis as the biconical trap. Acetone (500 mg/h) significantly increased trap catches of G. pallidipes, and there was a synergism between acetone and 4-methylphenol (0.8 mg/h). There was little or no effect with 1-octen-3-ol (0.8 mg/h). Acetone, 1-octen-3-ol, and 4-methylphenol all increased trap catches of G. longipennis, and there were no synergisms among them. Cow urine (850 mg/h) increased the catches of both species in traps baited with acetone and 1-octen-3-ol, although not significantly for G. longipennis. There was no effect with 3-methylphenol (0.8 mg/h). The addition of 3-propylphenol to traps baited with acetone, 1-octen-3-ol and 4-methylphenol had no effect on the catches of either species. For G.pallidipes, a combination of acetone, 1-octen-3-ol, 4-methylphenol and 3-propylphenol was calculated to have a catch index of 6–8 over unbaited traps, a value lower than that reported for Zimbabwe and Nguruman, Kenya, and greater than that reported for Somalia. The catches of G. longipennis were approximately three times higher on electrified targets than in F3 traps, although there was no difference in the catch of G. pallidipes.