Host plant use drives genetic differentiation in syntopic populations of Maculinea alcon Journal Article

Author(s): Tartally, András; Kelager, Andreas; Fürst, Matthias A; Nash, David R
Article Title: Host plant use drives genetic differentiation in syntopic populations of Maculinea alcon
Affiliation IST Austria
Abstract: The rare socially parasitic butterfly Maculinea alcon occurs in two forms, which are characteristic of hygric or xeric habitats and which exploit different host plants and host ants. The status of these two forms has been the subject of considerable controversy. Populations of the two forms are usually spatially distinct, but at Răscruci in Romania both forms occur on the same site (syntopically). We examined the genetic differentiation between the two forms using eight microsatellite markers, and compared with a nearby hygric site, Şardu. Our results showed that while the two forms are strongly differentiated at Răscruci, it is the xeric form there that is most similar to the hygric form at Şardu, and Bayesian clustering algorithms suggest that these two populations have exchanged genes relatively recently. We found strong evidence for population substructuring, caused by high within host ant nest relatedness, indicating very limited dispersal of most ovipositing females, but not association with particular host ant species. Our results are consistent with the results of larger scale phylogeographic studies that suggest that the two forms represent local ecotypes specialising on different host plants, each with a distinct flowering phenology, providing a temporal rather than spatial barrier to gene flow.
Keywords: Conservation units; Disruptive selection; Gentiana; Host specificity; Immigration; Maculinea rebeli; Myrmica; Phenological separation
Journal Title: PeerJ
Volume: 2016
Issue 3
ISSN: 2167-8359
Publisher: PeerJ  
Date Published: 2016-01-01
Start Page: Article number: 1865
Copyright Statement: CC BY 3.0
DOI: 10.7717/peerj.1865
Notes: AT was supported by a Marie Curie Intra-European Fellowship and a Marie Curie Career Integration Grant within the 7th European Community Framework Programme, and by a ‘Bolyai János’ scholarship of the Hungarian Academy of Sciences (MTA). AK and DRN were supported by a Danish National Research Foundation grant to the Centre for Social Evolution (DNRF57) and the Center for Macroecology, Evolution and Climate. We thank Tibor-Csaba Vizauer, László Rákosy and Zoltán Varga for assistance in the field and Shukriya Barzinci, Maria Mikkelsen and Sylvia Mathiasen for assistance in the laboratory. Zoltán Varga, Enikő Tóth, Simona Bonelli and Robert Toonen provided valuable comments on earlier versions of the manuscript.
Open access: yes (OA journal)