Genetic comparison of Glossina tachinoides populations in three river basins of the Upper West Region of Ghana and implications for tsetse control.
Tsetse flies are the cyclical vectors of African animal trypanosomosis (AAT) and human African trypanosomosis (HAT). In March 2010, the Government of Ghana initiated a large scale integrated tsetse eradication campaign in the Upper West Region (UWR) (≈18,000 km(2)) under the umbrella of the Pan-African Tsetse and Trypanosomosis Eradication Campaign (PATTEC). We investigated the structuring of Glossina tachinoides populations within and between the three main river basins of the target area in the UWR. Out of a total sample of 884 flies, a sub-sample of 266 was genotyped at nine microsatellite loci. The significance of the different hierarchical levels was tested using Yang's parameters estimated with Weir and Cockerham's method. A significant effect of traps within groups (pooling traps no more than 3 km distant from each other), of groups within river basins and of river basins within the whole target area was observed. Isolation by distance between traps was highly significant. A local density of 0.48-0.61 flies/m(2) was estimated and a dispersal distance that approximated 11 m per generation [CI 9, 17]. No significant sex-biased dispersal was detected. Dispersal distances of G. tachinoides in the UWR were relatively low, possibly as a result of the fragmentation of the habitat and the seasonality of the Kulpawn and Sissili rivers. Moreover, very high fly population densities were observed in the sample sites, which potentially reduces dispersal at constant habitat saturation, because the probability that migrants can established is reduced (density dependent dispersal). However, the observed spatial dispersal was deemed sufficient for a G. tachinoides-cleared area to be reinvaded from neighboring populations in adjacent river basins. These data corroborate results from other population genetics studies in West Africa, which indicate that G. tachinoides populations from different river basins cannot be considered isolated.
Veterinary Services Department of MOFA, P.O. Box 97, Pong-Tamale, Ghana. Electronic address: yahadamco@yahoo.com.
Y
Y
Adam
Cirad, UMR INRA-CIRAD Contrôle des maladies animales exotiques et émergentes, F-34398 Montpellier, France; Institut Sénégalais de Recherches Agricoles, Laboratoire National d'Elevage et de Recherches Vétérinaires, BP 2057, Dakar - Hann, Senegal. Electronic address: bouyer@cirad.fr.
J
J
Bouyer
Centre International de Recherche-Développement Sur l'Elevage en Zone Subhumide (CIRDES), 01 BP 454, Bobo-Dioulasso, Burkina Faso. Electronic address: charlesdayo@yahoo.fr.
G-K
GK
Dayo
Veterinary Services Department of MOFA, P.O. Box 97, Pong-Tamale, Ghana. Electronic address: cimahama@yahoo.com.
C I
CI
Mahama
Insect Pest Control Laboratory, Joint FAO/IAEA Program of Nuclear Techniques in Food and Agriculture, P.O. Box 100, Wagramerstrasse 4, A 1400 Vienna, Austria. Electronic address: M.Vreysen@iaea.org.
M J B
MJ
Vreysen
Food and Agriculture Organization of the United Nations, Sub-regional Office for Eastern Africa, CMC Road, P.O. Box 5536, Addis Ababa, Ethiopia. Electronic address: Giuliano.Cecchi@fao.org.
G
G
Cecchi
Insect Pest Control Laboratory, Joint FAO/IAEA Program of Nuclear Techniques in Food and Agriculture, P.O. Box 100, Wagramerstrasse 4, A 1400 Vienna, Austria. Electronic address: A.M.M.Abd-Alla@iaea.org.
A M M
AM
Abd-Alla
IRD, UMR 177 IRD-CIRAD Intertryp, CIRDES 01, BP 454, Bobo-Dioulasso 01, Burkina Faso. Electronic address: philippe.solano@ird.fr.
P
P
Solano
IRD, UMR 177 IRD-CIRAD Intertryp, TA A-17/G, Campus International de Baillarguet, 34398 Montpellier Cedex 5, France. Electronic address: sophie.ravel@ird.fr.
S
S
Ravel
IRD, UMR 177 IRD-CIRAD Intertryp, CIRDES 01, BP 454, Bobo-Dioulasso 01, Burkina Faso. Electronic address: thierry.demeeus@ird.fr.
T
T
de Meeûs
D000818:Animals; D005260:Female; D056426:Genetic Loci; D005828:Genetics, Population; D005838:Genotype; D005843:Geography; D005869:Ghana; D007178:Inbreeding; D007300:Insect Control; D008297:Male; D018895:Microsatellite Repeats / Q000235:genetics; D058889:Molecular Typing; D011156:Population Density; D011157:Population Dynamics; D060047:Reproductive Isolation; D045483:Rivers; D014370:Tsetse Flies / Q000235:genetics*
Dispersal; Population genetics; Population structure; Tsetse; Vector control