Parapatric distribution and sexual competition between two tick species, Amblyomma variegatum and A. hebraeum (Acari, Ixodidae), in Mozambique

Show simple item record Bournez, L. Cangi, Nidia Lancelot, R. Pleydell, D.R.J. Stachurski, F. Bouyer, Jerry Martinez, Dominique Lefrancois, T. Neves, L.C.B.G.D. (Luís) Pradel, J. 2015-11-16T06:24:25Z 2015-11-16T06:24:25Z 2015-10-06
dc.description.abstract BACKGROUND : Amblyomma variegatum and A. hebraeum are two ticks of veterinary and human health importance in south-east Africa. In Zimbabwe they occupy parapatric (marginally overlapping and juxtaposed) distributions. Understanding the mechanisms behind this parapatry is essential for predicting the spatio-temporal dynamics of Amblyomma spp. and the impacts of associated diseases. It has been hypothesized that exclusive competition between these species results from competition at the levels of male signal reception (attraction-aggregationattachment pheromones) or sexual competition for mates. This hypothesis predicts that the parapatry described in Zimbabwe could also be present in other countries in the region. METHODS : To explore this competitive exclusion hypothesis we conducted field surveys at the two species’ range limits in Mozambique to identify areas of sympatry (overlapping areas) and to study potential interactions (communicative and reproductive interference effects) in those areas. At sympatric sites, hetero-specific mating pairs were collected and inter-specific attractiveness/repellent effects acting at long and short distances were assessed by analyzing species co-occurrences on co-infested herds and co-infested hosts. RESULTS : Co-occurrences of both species at sampling sites were infrequent and localized in areas where both tick and host densities were low. At sympatric sites, high percentages of individuals of both species shared attachment sites on hosts and inter-specific mating rates were high. Although cross-mating rates were not significantly different for A. variegatum and A. hebraeum females, attraction towards hetero-specific males was greater for A. hebraeum females than for A. variegatum females and we observed small asymmetrical repellent effects between males at attachment sites. CONCLUSIONS : Our observations suggest near-symmetrical reproductive interference between A. variegatum and A. hebraeum, despite between-species differences in the strength of reproductive isolation barriers acting at the aggregation, fixation and partner contact levels. Theoretical models predict that sexual competition coupled with hybrid inviability, greatly reduces the probability of one species becoming established in an otherwise suitable location when the other species is already established. This mechanism can explain why the parapatric boundary in Mozambique has formed within an area of low tick densities and relatively infrequent host-mediated dispersal events. en_ZA
dc.description.librarian am2015 en_ZA
dc.description.sponsorship European project, FEDER 2007–2013, FED 1/1.4-30305, “Gestion des Risquesen santé animale et végétale”, from the INRA “molecular biology – epidemiology” project and from the Centre of Biotechnology of the University of Maputo, Eduardo Mondlane. Laure Bournez acknowledges financial support for her PhD from the European project, FED 1/1.4-30305 and CIRAD. en_ZA
dc.description.uri en_ZA
dc.identifier.citation Bournez, L, Cangi, N, Lancelot, R, Pleydell, DRJ, Stachurski, F, Bouyer, J, Martinez, D, Lefrancois, T, Neves, L & Pradel, J 2015, 'Parapatric distribution and sexual competition between two tick species, Amblyomma variegatum and A. hebraeum (Acari, Ixodidae), in Mozambique', Parasites & Vectors, vol. 8, art. no. 504, pp. 1-14. en_ZA
dc.identifier.issn 1756-3305
dc.identifier.other 10.1186/s13071-015-1116-7
dc.language.iso en en_ZA
dc.publisher BioMed Central en_ZA
dc.relation.requires Adobe Acrobat Reader en
dc.rights © 2015 Bournez et al. Open Access This article is distributed under the terms of the Creative Commons Attribution 4.0 International License. en_ZA
dc.subject Exclusive competition en_ZA
dc.subject Reproductive interference en_ZA
dc.subject Communicative interference en_ZA
dc.subject Parapatry en_ZA
dc.subject Hybrid inviability en_ZA
dc.title Parapatric distribution and sexual competition between two tick species, Amblyomma variegatum and A. hebraeum (Acari, Ixodidae), in Mozambique en_ZA
dc.type Article en_ZA

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