Tsetse flies are attracted to the invasive plant Lantana camara

Abstract

In tsetse both sexes feed exclusively on the blood of vertebrates for a few minutes every 2-3 days. Tsetse flies seek cover from high temperatures to conserve energy and plants provide shelter for tsetse in all the biotopes they occupy. Recently, tsetse have taken cover in plantations and under the invasive bush Lantana camara that has invaded large areas of the tsetse fly belt of Africa. Flies from such refugia are implicated in sleeping sickness epidemics. In a wind tunnel we show that both foliage and an extract of volatiles from foliage of L. camara attract three tsetse spp. from different habitats: Glossina fuscipes fuscipes (riverine), G. brevipalpis (sylvatic) and G. pallidipes (savannah).Gas chromatography analysis of volatiles extracted from leaves and flowers of L. camara coupled to electroantennograme recordings show that 1-octen-3-ol and b-caryophyllene are the major chemostimuli for the antennal receptor cells of the three tsetse spp. studied. A binary mixture of these products attracted these flies in the wind tunnel. The gas chromatography linked electroantennograme analysis of the L. camara extracts also show that the antennal receptor cells of the three tsetse spp. respond similarly to groups of volatiles derived from the major biosynthetic and catabolic pathways of plants, i.e. to mono-and sesquiterpenes, to lipoxidation products and to aromatics. Mixtures of these plant volatiles also attracted tsetse in the wind tunnel. These findings show that tsetse flies have conserved a strong sensitivity to volatile secondary products of plants, underlining the fundamental role of vegetation in tsetse survival.

Olfactory and behavioural responses of tsetse flies, Glossina spp., to rumen metabolites

“…As most of these compounds pass untransformed through the digestive system of ruminants, they occur in bovid rumen Xuid and breath, but their identity in a particular host largely depends on the plant types the animal has fed on. Two terpenes that tsetse showed EAG responses to in this study, namelycaryophyllene and germacrene D were previously identiWed in volatiles collected from the invasive plant Lantana camara (Syed and Guerin 2004) that is used by tsetse Xies as a refuge from the high daytime temperatures of Africa (Okoth and Kapaata 1987). As terpenes from plants used as refugia by tsetse Xies can also occur in hosts, these insects are probably making parsimonious use of chemostimuli to guide them to diVerent resources.…”

“…Two diVerent setups were used for the behavioural experiments: the method already described in Syed and Guerin (2004) was used to test the responses of G. pallidipes to the odour of the rumen Xuid, whereas the method explained below was employed to test the responses of G. pallidipes and G. brevipalpis to known compounds.…”

“…However, since the initial isolation of semiochemicals for tsetse, little research on molecules inXuencing tsetse Xy sensory ecology has been undertaken, even though Weld experiments had shown that tsetse Xies are able to react to a larger variety of chemostimuli (Vale 1980;Torr et al 1996;IAEA-TECDOC 2003). More recently, laboratory experiments have shown that tsetse Xies of the three subgenera are attracted to plant compounds in a wind tunnel (Syed and Guerin 2004).…”

Parasitism data of Glossina palpalis and G. tachinoides (Diptera: Glossinidae) by trypanosome species in parts of Abia State, Nigeria

“…Tsetse flies are blood-sucking dipterans in which both male and female feed exclusively on the blood of vertebrates for a few minutes every 2-3 days. 1 The flies seek cover from high temperatures to conserve energy and plants provide shelter in all the biotypes. In some cases the flies take cover in plantations and under invasive bush in many areas of the tsetse fly belt of Africa and flies from such refugia are implicated in sleeping sickness epidemics.…”

1-octen-3-O-alpha-L-arabinopyranosyl-(1 -> 6)-beta-glucopyranoside, a minor substance from the leaves of Kalanchoe pinnata (Crassulaceae)

“…The ability of some insects to respond to olfactory stimuli can explain their propensity to fi nd suitable cover under a specifi c group of plant (Syed;Guerin, 2004).…”