Data from: Bombus impatiens colony microsatellite genotype data for mating frequency analysis

The genus Bombus (bumble bees) includes approximately 265
species, many of which are in decline in North America and Europe. To
estimate the colony abundance of bumble bees in natural and agricultural
habitats, sibship relationships are often reconstructed from genetic data
with the assumption that colonies have one monandrous queen. However, some
species such as the North American common eastern bumble bee (Bombus
impatiens Cresson) can display low levels of polyandry, which may bias
estimates of colony abundance based on monandrous sibship reconstructions.
To accurately quantify rates of polyandry in wild and commercially mated
queens of this species, we empirically estimated mating frequencies using
a novel statistical model and genotypes from 730 bees. To genotype
individuals, we used a highly polymorphic set of microsatellites on
colonies established from 20 wild-caught gynes and 10 commercial colonies.
We found multiple fathers in three of the wild colonies and three of the
commercial colonies. This resulted in average effective mating frequencies
of 1.075 ± 0.18 and 1.154 ± 0.25 for wild and commercial colonies,
respectively. These findings agree with previous reports of low rates of
polyandry for B. impatiens. Using a large empirical dataset, we
demonstrate that assuming monandry for colony abundance estimation in
species that violate this assumption results in an overestimation of the
number of colonies. Our results emphasize the importance of studying
mating frequencies in social species of conservation concern and economic
importance for the accuracy of colony abundance estimation and for
understanding their ecology and sociobiology.