A survivor population of wild colonies of European honeybees in the northeastern United States: investigating its genetic structure

Abstract

-There is a widespread belief that wild colonies of European honeybees have been eradicated in Europe and North America, killed by viruses spread by the introduced ectoparasitic mite, Varroa destructor. In reality, however, several populations of wild colonies of honeybees in Europe and North America are persisting despite exposure to Varroa . To help understand how this is happening, we tested whether the bees in one of these populations of wild colonies-those living in and around the Arnot Forest (NY, USA)-are genetically distinct from the bees in the nearest managed colonies. We found that the Arnot Forest honeybees are genetically distinct from the honeybees in the two apiaries within 6 km of the forest. Evidently, the population of Arnot Forest honeybees is not supported by a heavy influx of swarms from the nearest managed colonies, which implies that it is self-sustaining. These results suggest that if a closed population of honeybee colonies is allowed to live naturally, it will develop a balanced relationship with its agents of disease. Indeed, it is likely to become well adapted to its local environment as a whole. We suggest four ways to modify beekeeping practices to help honeybees live in greater health.host-parasite coevolution / avirulence / survivor population / wild honeybees / Arnot Forest

Distance between honey bee Apis mellifera colonies regulates populations of Varroa destructor at a landscape scale

“…The continuity of lower mite numbers in the 100 m apiaries suggests a biologically meaningful threshold. This finding is consistent with that for the comparatively large inter-colony distances found in nature (range=304–4848 m; see Introduction, Seeley et al 2015). …”

“…Average inter-colony distances in nature range from 304–4848 m (mean=2326 ± SD=1031; n =45; derived from Fig. 1, Seeley et al 2015), whereas distances in apiaries are smaller by orders of magnitude with inter-colony distances of 1 m not uncommon. With a range of possibilities this wide, we decided to focus on and replicate inter-colony distance to nearest neighbor as a driver in mite emigration and population growth.…”

Risks and benefits of the biological interface between managed and wild bee pollinators

“…Africanized honeybees seem to be less affected by Varroa mites than their European sister subspecies in Europe and North America (Ruttner, Marx & Marx ; Medina & Martin ; Seeley et al . ).…”

Crowding honeybee colonies in apiaries can increase their vulnerability to the deadly ectoparasite Varroa destructor

“…In medieval Russia, for example, the honeybees inhabiting trees in the forests around the city of Nizhny Novgorod had a density of 1-2 colonies per km 2 (Galton 1971), hence they were spaced, on average, 700-1,000 m apart. Similarly, in the USA today, the honeybee colonies nesting in tree cavities in the forests around Ithaca, New York have a density of approximately 1 colony per km 2 and a mean nearest-neighbor distance of 850 m (see maps in Seeley 2007;Seeley et al 2015). In contrast, the honeybees residing in hives in apiaries around the world have nearest-neighbor distances that are often only about 1 m (see photos of apiaries in Crane 1983Crane , 1999.…”