title: A century of temporal stability of genetic diversity in wild bumblebees.
abstract: Since the 1950s, bumblebee (Bombus) species are showing a clear decline worldwide. Although many plausible drivers have been hypothesized, the cause(s) of this phenomenon remain debated. Here, genetic diversity in recent versus historical populations of bumblebee species was investigated by selecting four currently restricted and four currently widespread species. Specimens from five locations in Belgium were genotyped at 16 microsatellite loci, comparing historical specimens (1913-1915) with recent ones (2013-2015). Surprisingly, our results showed temporal stability of genetic diversity in the restricted species. Furthermore, both historical and recent populations of restricted species showed a significantly lower genetic diversity than found in populations of co-occurring widespread species. The difference in genetic diversity between species was thus already present before the alleged recent drivers of bumblebee decline could have acted (from the 1950's). These results suggest that the alleged drivers are not directly linked with the genetic variation of currently declining bumblebee populations. A future sampling in the entire distribution range of these species will infer if the observed link between low genetic diversity and population distribution on the Belgium scale correlates with species decline on a global scale.
authors.affiliation: Department of Crop Protection, Faculty of Bioscience Engineering, Ghent University, Coupure links 653, B-9000, Ghent, Belgium.
authors.forename: Kevin
authors.initials: K
authors.lastname: Maebe
authors.affiliation: Department of Crop Protection, Faculty of Bioscience Engineering, Ghent University, Coupure links 653, B-9000, Ghent, Belgium.
authors.forename: Ivan
authors.initials: I
authors.lastname: Meeus
authors.affiliation: Laboratoire de Zoologie, University of Mons, Place du Parc 20, B-7000 Mons, Belgium.|Department of Geography, University of Namur, Rue de Bruxelles 61, B-5000 Namur, Belgium.
authors.forename: Sarah
authors.initials: S
authors.lastname: Vray
authors.affiliation: Department of Crop Protection, Faculty of Bioscience Engineering, Ghent University, Coupure links 653, B-9000, Ghent, Belgium.
authors.forename: Thomas
authors.initials: T
authors.lastname: Claeys
authors.affiliation: Royal Belgian Institute of Natural Sciences, Vautierstraat 29, B-1000 Brussels, Belgium.
authors.forename: Wouter
authors.initials: W
authors.lastname: Dekoninck
authors.affiliation: Royal Belgian Institute of Natural Sciences, Vautierstraat 29, B-1000 Brussels, Belgium.
authors.forename: Jean-Luc
authors.initials: JL
authors.lastname: Boevé
authors.affiliation: Laboratoire de Zoologie, University of Mons, Place du Parc 20, B-7000 Mons, Belgium.
authors.forename: Pierre
authors.initials: P
authors.lastname: Rasmont
authors.affiliation: Department of Crop Protection, Faculty of Bioscience Engineering, Ghent University, Coupure links 653, B-9000, Ghent, Belgium.
authors.forename: Guy
authors.initials: G
authors.lastname: Smagghe
mesh_terms: D063147:Animal Distribution; D000818:Animals; D001516:Bees / Q000033:anatomy & histology / Q000145:classification / Q000235:genetics*; D001530:Belgium; D005260:Female; D014644:Genetic Variation; D005828:Genetics, Population; D049750:Genome, Insect; D005838:Genotype; D008297:Male; D018895:Microsatellite Repeats; D010802:Phylogeny; D011156:Population Density