title: Do tsetse flies only feed on blood?
abstract: Tsetse flies (Diptera: Glossinidae) are the vectors of trypanosomes causing sleeping sickness in humans, and nagana (animal trypanosomosis) in domestic animals, in Subsaharan Africa. They have been described as being strictly hematophagous, and transmission of trypanosomes occurs when they feed on a human or an animal. There have been indications however in old papers that tsetse may have the ability to digest sugar. Here we show that hungry tsetse (Glossina palpalis gambiensis) in the lab do feed on water and on water with sugar when no blood is available, and we also show that wild tsetse have detectable sugar residues. We showed in laboratory conditions that at a low concentration (0.1%) or provided occasionally (0.1%, 0.5%, 1%), glucose had no significant impact on female longevity and fecundity. However, regular provision of water with 1% glucose increased the mortality and reduced the fecundity of female G. p. gambiensis. The proportion of wild tsetse caught by traps, which have detectable sugar residue in their midgut varied between 5 and 10% according to species (p<10(-3)) and sex, with more females being found with sugar residues than males (p<10(-3)). We also observed a higher frequency of sugar residues in the dry season than in the rainy season (p<10(3)). The infection status did not affect the frequency of sugar residues found (p=0.65), neither did age (p=0.23). These observations represent a fundamental change in our knowledge of this insect vector. They open the way for further research on the field to know more on tsetse feeding behavior regarding other sources of meal than blood, in particular with plants, and may constitute future new means of controlling this vector of neglected tropical diseases.
authors.affiliation: IRD, UMR INTERTRYP, F-34398 Montpellier, France.
authors.forename: Philippe
authors.initials: P
authors.lastname: Solano
authors.affiliation: Université Polytechnique de Bobo Dioulasso (UPB), Burkina Faso; CIRDES, BP454 Bobo-Dioulasso, Burkina Faso.
authors.forename: Ernest
authors.initials: E
authors.lastname: Salou
authors.affiliation: CIRDES, BP454 Bobo-Dioulasso, Burkina Faso.
authors.forename: Jean-Baptiste
authors.initials: JB
authors.lastname: Rayaisse
authors.affiliation: IRD, UMR INTERTRYP, F-34398 Montpellier, France.
authors.forename: Sophie
authors.initials: S
authors.lastname: Ravel
authors.affiliation: CIRAD, UMR CMAEE, Dakar-Hann, Sénégal; INRA, UMR1309 CMAEE, F-34398 Montpellier, France; CIRAD, UMR INTERTRYP, F-34398 Montpellier, France; ISRA, LNERV, Dakar-Hann, Sénégal.
authors.forename: Geoffrey
authors.initials: G
authors.lastname: Gimonneau
authors.affiliation: CIRDES, BP454 Bobo-Dioulasso, Burkina Faso.
authors.forename: Ibrahima
authors.initials: I
authors.lastname: Traore
authors.affiliation: CIRAD, UMR CMAEE, Dakar-Hann, Sénégal; INRA, UMR1309 CMAEE, F-34398 Montpellier, France; CIRAD, UMR INTERTRYP, F-34398 Montpellier, France; ISRA, LNERV, Dakar-Hann, Sénégal; CIRAD, UMR CMAEE, F-34398 Montpellier, France. Electronic address: bouyer@cirad.fr.
authors.forename: Jérémy
authors.initials: J
authors.lastname: Bouyer
mesh_terms: D000818:Animals; D000873:Anthracenes; D001769:Blood; D005247:Feeding Behavior / Q000502:physiology*; D005260:Female; D005298:Fertility / Q000187:drug effects; D005947:Glucose / Q000494:pharmacology; D006801:Humans; D007303:Insect Vectors / Q000502:physiology*; D008136:Longevity / Q000187:drug effects; D008297:Male; D014352:Trypanosomiasis; D014370:Tsetse Flies / Q000737:chemistry / Q000187:drug effects / Q000502:physiology*; D000095322:Anthrones
chemical_list: D000873:Anthracenes; D005947:Glucose; C004522:anthrone; D000095322:Anthrones
keywords: Feeding behavior; Hematophagous; Sugar; Trypanosomosis; Tsetse; Vector