Effect of sampling methods, effective population size and migration rate estimation in Glossina palpalis palpalis from Cameroon Tanekou Tito Trésor Mélachio a , Flobert Njiokou a , Sophie Ravel b , Gustave Simo c , Philippe Solano b,d , Thierry De Meeûs b,d,⇑ a University of Yaounde I, Laboratory of Parasitology and Ecology, Faculty of Science, BP 812 Yaounde, Cameroon b Institut de Recherche pour le Développement (IRD), UMR IRD/CIRAD 177 INTERTRYP, TA A-17/G, Campus International de Baillarguet, 34398 Montpellier Cedex 5, France c Molecular Parasitology and Entomology Unit, Department of Biochemistry, Faculty of Science, University of Dschang, Dschang, Cameroon d UMR 177 IRD/CIRAD INTERTRYP, Centre International de Recherche-Développement sur l’Elevage en zone Subhumide (CIRDES), 01 BP 454 Bobo-Dioulasso 01, Burkina Faso article info Article history: Received 18 December 2014 Received in revised form 22 April 2015 Accepted 24 April 2015 Available online 25 April 2015 Keywords: Glossina palpalis palpalis Heterozygote deficits Sampling methods Migration rate Effective population size Wahlund effect abstract Human and animal trypanosomiases are two major constraints to development in Africa. These diseases are mainly transmitted by tsetse flies in particular by Glossina palpalis palpalis in Western and Central Africa. To set up an effective vector control campaign, prior population genetics studies have proved use- ful. Previous studies on population genetics of G. p. palpalis using microsatellite loci showed high heterozygote deficits, as compared to Hardy–Weinberg expectations, mainly explained by the presence of null alleles and/or the mixing of individuals belonging to several reproductive units (Wahlund effect). In this study we implemented a system of trapping, consisting of a central trap and two to four satellite traps around the central one to evaluate a possible role of the Wahlund effect in tsetse flies from three Cameroon human and animal African trypanosomiases foci (Campo, Bipindi and Fontem). We also esti- mated effective population sizes and dispersal. No difference was observed between the values of allelic richness, genetic diversity and Wright’s F IS , in the samples from central and from satellite traps, suggest- ing an absence of Wahlund effect. Partitioning of the samples with Bayesian methods showed numerous clusters of 2–3 individuals as expected from a population at demographic equilibrium with two expected offspring per reproducing female. As previously shown, null alleles appeared as the most probable factor inducing these heterozygote deficits in these populations. Effective population sizes varied from 80 to 450 individuals while immigration rates were between 0.05 and 0.43, showing substantial genetic exchanges between different villages within a focus. These results suggest that the ‘‘suppression’’ with establishment of physical barriers may be the best strategy for a vector control campaign in this forest context. Ó 2015 Elsevier B.V. All rights reserved. 1. Introduction Glossina palpalis palpalis (Diptera, Glossinidae) is a major vector of human and animal African trypanosomiases in Western and Central Africa. Human African Trypanosomiasis (HAT) is a lethal neglected tropical disease which remains a serious public health problem in many endemic countries, with a total incidence of about 10,000 cases a year (Simarro et al., 2011). Animal African try- panosomiasis (AAT) is responsible for dramatic economic losses in sub-Saharan Africa, estimated at about 4.5 billion US$ per year (FAO, 1999). There is no vaccine for these diseases. HAT control based on diagnosis and treatment of patients has led to a great reduction of the incidence of the disease and its maintenance at low prevalence in most affected countries. However, the disease continues to spread because the tsetse vector is still present and continues to play its transmission role. Therefore, the control of the tsetse vector appears necessary for controlling HAT. Nevertheless, past efforts to eliminate tsetse ended in failure because the treated zones were later re-colonized by tsetse from neighboring areas and/or remaining survivors. Nonetheless, there has been successful eradication of tsetse in Unguja Island in Zanzibar (Vreysen et al., 2000) where the tsetse population was geographically isolated. On mainland, where the geographic limits of tsetse populations are less definable, population genetic studies have shown different levels of structuring in tsetse populations. Estimating gene flow between subpopulations, and population http://dx.doi.org/10.1016/j.meegid.2015.04.023 1567-1348/Ó 2015 Elsevier B.V. All rights reserved. ⇑ Corresponding author at: UMR 177 IRD/CIRAD INTERTRYP, Centre International de Recherche-Développement sur l’Elevage en zone Subhumide (CIRDES), 01 BP 454 Bobo-Dioulasso 01, Burkina Faso. E-mail address: thierry.demeeus@ird.fr (T. De Meeûs). Infection, Genetics and Evolution 33 (2015) 150–157 Contents lists available at ScienceDirect Infection, Genetics and Evolution journal homepage: www.elsevier.com/locate/meegid