Abstract
Several population genetic studies investigated the extent of gene flow and population connectivity in bumblebees. In general, no restriction in gene flow is considered for mainland populations of common bumblebee species. Whether this assumption holds true for all species is not known. An assessment of bumblebee genetic structure in the context of their geographic distribution is needed to prioritize conservation and management needs. Here, we conducted a genetic study on seven bumblebee species occurring in Belgium and Estonia. Using 16 microsatellite markers, we investigated genetic diversity and population structuring in each species. This is the first study investigating population structuring of both declining and stable bumblebee species on both small and large geographic scales. Our results showed no or only low population structuring between the populations of the restricted and declining bumblebee species on both scales, while significant structuring was found for populations of the common species on the larger scale. The latter result, which may be due to human or environmental changes in the landscape, implies the need for the conservation of also widespread bumblebee species. Conservation strategies to improve gene flow and connectivity of populations could avoid the isolation and future losses of populations of these important species.
Highlights
Bumblebees are essential pollinators for natural and managed ecosystems[1,2]
We tested the hypotheses that (i) population structuring is absent between populations of common bumblebee species on both scales, while (ii) between populations of restricted and declining species gene flow can be limited at the small scale and structuring should be present at the larger geographic scale
For the common bumblebee species we found no population structuring on a small scale but on the large scale population structuring was present in three out of the four common species
Summary
Bumblebees are essential pollinators for natural and managed ecosystems[1,2]. They experience worldwide declines, even more severe than many other pollinator species[3,4,5]. The amount of reproductive offspring a species produces will contribute to the level of gene flow, as more reproductives may enlarge the chance of successful matings and exchange of genetic material between populations (as discussed in[24]) Geographical barriers, such as water bodies and mountains, can greatly limit dispersal and gene flow[25]. These studies showed the impact of www.nature.com/scientificreports/ Such geographic barriers, as they reported an increased population genetic differentiation for mountain and island species[12,17,23,24,25,26,27,28,29,30], and a significant fine-scale spatial genetic structure for B. vosnesenskii[30] due to human altered-landscapes[17]. An assessment of bumblebee genetic structure in the context of their geographic distribution is needed to help prioritize conservation and management needs (as stated by[12])
Sign-in/Register to view highlights & summary Sign-in/Register to access full text options 
Free) 
Talk to us
Join us for a 30 min session where you can share your feedback and ask us any queries you have
Schedule a call
