Olfactory attractants for West African tsetse flies, glossina spp. (Diptera: Glossinidae)

The effect of various natural host odours on Glossina longipalpis, G. medicorum and G. tachinoides from catches in odour-baited biconical traps was analysed. Substances tested were ox urine, and the eight components of its phenolic fraction, as well as acetone and 1-octen-3-ol, both of which are present in ox breath. Ox urine increased the catch of G. tachinoides significantly by 1.2 times. Its phenolic fraction gave increases of up to 1.6 for G. longipalpis and 1.4 for G. tachinoides (significant in both cases). Adding acetone and/or 1-octen-3-ol to the phenolic fraction increased attraction of G. longipalpis and G. tachinoides significantly by up to 1.8 and 1.3 times, respectively. Octenol on its own increased the catch of all three species significantly by up to 2.2 times. Acetone alone, in combination with octenol or with the phenolic fraction reduced the catch of G. medicorum significantly to a level of 0.2. 3-Methylphenol and 4-methylphenol are those components of the phenolic fraction which showed the highest attractiveness on tsetse flies in the experiments. Several mixtures of both methylphenols and/or 1-octen-3-ol were tested as attractants for all three tsetse species.