Results of a two-year Nosema monitoring in Southern Germany

Publication Type

Poster

Authors

ODEMER, Richard, HARSCH, T., LARUE, A-A., ROSENKRANZ, P.

Year of publication

2012

Conference name

EURBEE

Conference location

Halle/Saale

There are contrasting reports on the prevalence and pathogenicity of Nosemosis from different parts of Europe. We therefore performed a monitoring project to follow the course of Nosema infestation in different apiaries in South Germany. From April 2010 - October 2011, more than 60 honeybee colonies from 14 apiaries were examined for the occurrence of Nosema spores in monthly intervals. In total, more than 450 samples of 60 bees collected from a peripheral honey comb were quantified for the number of spores. Throughout the whole monitoring period none of the colonies were completely free from Nosema spores. In both years, the highest prevalence was recorded during spring in April/May with about 90% of Nosema positive colonies. At the end of the season merely 50% of the colonies were infested with huge differences between the apiaries. The maximum average infestation rate of one colony was 4.700.00 spores per bee, however, only 7% of the samples revealed infestation rates of more than 1.000.000 spores per bee. During the whole sampling period no clinical symptoms and no winter losses caused by Nosemosis were reported by the beekeeper involved in the project. Molecular genetic analysis of the positive samples showed that Nosema ceranae was the exclusive Nosema species within our monitored apiaries. These confirm results of monitoring project of BEE DOC partners from other European countries and contradict reports of severe damages caused by infections with N. ceranae. Supported by the EU project “BEE DOC” (244956 CP-FP)“.