Natural host odours as possible attractants for Glossina tachinoides and G. longipalpis (Diptera: Glossinidae)

As strictly haematophagous insects, tsetse flies feed on a wide variety of wild and domestic animals. Although these are mainly mammals, some tsetse species also feed on reptiles. The present study investigated whether the odours of several potential natural tsetse hosts may be used as novel attractants to improve the catch of Glossina tachinoides or G. longipalpis in biconical traps. The odour of a living monitor lizard (Varanus niloticus) had no effect on the catch of G. tachinoides. Hexane skin washings of monitor lizard and warthog (Phacochoerus aethiopicus) dispensed in small quantities improved the catch of G. tachinoides significantly by factors of up to 1.34 and 1.46, respectively. Skin washing of bushbuck (Tragelaphus scriptus) did not increase the catch of G. tachinoides, but the synthetic phenolic fraction of bushbuck urine enhanced it significantly by 1.81 times. The catch of G. longipalpis was improved significantly by the urines of warthog, domestic pig and bushbuck by factors of 1.58, 1.91 and 2.51, respectively. In relation to the quantity of evaporated odour, bushbuck and warthog urine seem to be of particular interest for further attractant studies. The effect of tested host odours on the catch of G. tachinoides and G. longipalpis is compared with data of other tsetse species and with the frequency these hosts are fed on by tsetse flies. Bushbuck is one of the principal natural hosts of both Glossina species investigated, and of all odours tested, bushbuck urine and its synthetic phenolic fraction improved the catch of both tsetse species the most.