An Observational Study of Honey Bee Colony Winter Losses and Their Association with Varroa destructor, Neonicotinoids and Other Risk Factors.

This article presents results of an analysis of honey bee losses over the winter of 2011-2012 in the Netherlands, from a sample of 86 colonies, located at 43 apiaries. The apiaries were selected using spatially stratified random sampling. Colony winter loss data were collected and related to various measures of colony strength recorded in summer, as well as data from laboratory analysis of sample material taken from two selected colonies in each of the 43 apiaries.

Virulence and polar tube protein genetic diversity of Nosema ceranae (Microsporidia) field isolates from Northern and Southern Europe in honeybees (Apis mellifera iberiensis).

Infection of honeybees by the microsporidian Nosema ceranae is considered to be one of the factors underlying the increased colony losses and decreased honey production seen in recent years. However, these effects appear to differ in function of the climatic zone, the distinct beekeeping practices and the honeybee species employed. Here, we compared the response of Apis mellifera iberiensis worker bees to experimental infection with field isolates of N.