Phenetic and genetic structure of tsetse fly populations (Glossina palpalis palpalis) in southern Ivory Coast

Abstract

BackgroundSleeping sickness, transmitted by G. p. palpalis, is known to be present in the Ivory Coast. G. p. palpalis has recently been reported to occur in several places within the town of Abidjan, including: (i) the Banco forest, (ii) the Abobo Adjamé University campus and (iii) the zoological park. Could these three places be treated sequentially, as separate tsetse populations, or should they be taken as one area comprising a single, panmictic population?MethodsThe amount of gene flow between these places provides strategic information for vector control. It was estimated by the use of both microsatellite DNA and morphometric markers. The idea was to assess the interest of the faster and much less expensive morphometric approach in providing relevant information about population structure. Thus, to detect possible lack of insect exchange between these neighbouring areas of Abidjan, we used both genetic (microsatellite DNA) and phenetic (geometric morphometrics) markers on the same specimens.Using these same markers, we also compared these samples with specimens from a more distant area of south Ivory Coast, the region of Aniassué (186 km north from Abidjan).ResultsNeither genetic nor phenetic markers detected significant differentiation between the three Abidjan G. p. palpalis samples. Thus, the null hypothesis of a single panmictic population within the city of Abidjan could not be rejected, suggesting the control strategy should not consider them separately. The markers were also in agreement when comparing G. p. palpalis from Abidjan with those of Aniassué, showing significant divergence between the two sites.ConclusionsBoth markers suggested that a successful control of tsetse in Abidjan would require the three Abidjan sites to be considered together, either by deploying control measures simultaneously in all three sites, or by a continuous progression of interventions following for instance the "rolling carpet" principle. To compare the geometry of wing venation of tsetse flies is a cheap and fast technique. Agreement with the microsatellite approach highlights its potential for rapid assessment of population structure.

Effects of vector control on the population structure of tsetse ( Glossina fuscipes fuscipes ) in western Kenya

“…Previous studies on population structures of tsetse have shown a strong correlation between morphometrics results with methods that are based on genetics and cuticular hydrocarbons (Bouyer et al, 2007b;Camara et al, 2006;Getahun et al, 2014;Kaba et al, 2012).…”

“…However, controlling the vector is considered the most desirable way of managing African trypanosomiasis (Bouyer et al, 2010;Leak, 1998;Vreysen et al, 2013) but, in the absence of area-wide control interventions covering biologically relevant areas and targeting isolated tsetse populations, re-invasion is commonly reported (Bouyer et al, 2007b;Kaba et al, 2012;Schofield and Kabayo, 2008). Some vector control techniques such as the use of targets exploit the host seeking behaviour which to a larger extent depends on the displacement rates of the tsetse fly (Vale et al, 2014).…”

“…Fly size is one of the indicators of tsetse population structures and can be obtained from wing measurement (Kaba et al, 2012;Solano et al, 1999). Inter-species variation in tsetse fly size has been associated with differences in displacement rates, responses to attractive and repellent odours, availability to tiny or large targets, persistence and landing responses (Torr et al, 2011;Vale, 1974;Vale et al, 2014Vale et al, , 1984.…”

Geometric morphometric analysis of the effect of temperature on wing size and shape in Aedes albopictus

“…Landmark-based geometric morphometrics has been used to investigate many insect vectors, such as sandflies, tsetse flies, Culicoides spp. and mosquitoes (De la Riva et al, 2001;Aytekin et al, 2009;Muñoz-Muñoz et al, 2011;Kaba et al, 2012;Sumruayphol et al, 2016Sumruayphol et al, , 2017. In addition, outline-based geometric morphometrics has been recently successfully used to classify various important arthropods, such as ticks, mosquitoes, tsetse flies and kissing bugs (Dujardin et al, 2014;Jaramillo et al, 2015;Sumruayphol et al, 2016).…”

Caracterização de populações de Culex coronator (Diptera: Culicidae) e distinção de fêmeas adultas de Culex coronator e Culex usquatus por meio da análise da morfometria geométrica de asa e de sequências gênicas

“…In this sense, geometric morphometrics can be used to quantify this variation. Currently, this method has been largely employed both in distinction of closely related species [28][29][30][31] as in microevolution studies [32][33][34][35][36]. Considering the lack of biological and ecological studies regarding Cx.…”