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Honeybees (Apis mellifera L.) have an extreme polyandrous mating system. Worker offspring of 19 naturally mated queens was genotyped with DNA microsatellites, to estimate male reproductive success of 16 drone producing colonies. This allowed for estimating the male mating success on both the colony level and the level of individual drones. The experiment was conducted in a closed population on an isolated island to exclude interferences of drones from unknown colonies. Although all colonies had produced similar numbers of drones, differences among the colonies in male mating success exceeded one order of magnitude. These differences were enhanced by the siring success of individual drones within the offspring of mated queens. The siring success of individual drones was correlated with the mating frequency at the colony level. Thus more successful colonies not only produced drones with a higher chance of mating, but also with a significantly higher proportion of offspring sired than drones from less successful colonies. Although the life cycle of honeybee colonies is very female centred, the male reproductive success appears to be a major driver of natural selection in honeybees.

Publication details, including instructions for authors and subscription information: http://www.tandfonline.com/loi/tjar20 A survey on some factors potentially affecting losses of managed honey bee colonies in Luxembourg over the winters

Pesticide residues (112 compounds) were quantified by GC-MS/MS or LC-MS/MS in 85 bee bread samples and 154 pollen samples obtained from five apiaries each with three or four colonies (genotype Buckfast) in Luxembourg over the period 2011-2013. Thiacloprid, chlorfenvinphos, tebuconazole, and methiocarb were found most frequently in bee bread while thiacloprid, permethrin-cis, and permethrin-trans were detected most frequently in the pollen samples. Three neonicotinoid insecticides (clothianidin, imidacloprid, and thiamethoxam) that were restricted by an EU regulation in 2013 after our sampling campaign was finished were each found in less than 8% of the pollen or bee bread samples. The maximum concentrations of thiacloprid, metazachlor, and methiocarb measured in the pollen collected by a group of honeybee colonies (n = 5) without survivors within the 3-year period of observation were 86.20 ± 10.74 ng/g, 2.80 ± 1.26 ng/g, and below the limit of quantification, respectively. The maximum concentrations of the same compounds measured in the pollen collected by a group of honeybee colonies with significantly (P = 0.02) more survivors (7 out of 9) than expected, if the survivors had been distributed randomly among the groups of colonies, were 11.98 ± 2.28 ng/g, 0.44 ± 0.29 ng/g, and 8.49 ± 4.13 ng/g, respectively. No honeybee colony that gathered pollen containing more than 23 ng/g thiacloprid survived the 3-year project period. There was no statistically significant association between pesticide residues in the bee bread and the survival of the colonies. Actions already taken or planned and potential further actions to protect bees from exposure to pesticides are discussed.