6 research outputs found
Spatial clusters of Varroa destructor control strategies in Europe
Publication history: Accepted - 18 May 2022; Published online - 29 June 2022Beekeepers have various options to control the parasitic mite Varroa destructor in honey bee colonies, but no empirical data
are available on the methods they apply in practice. We surveyed 28,409 beekeepers maintaining 507,641 colonies in 30
European countries concerning Varroa control methods. The set of 19 diferent Varroa diagnosis and control measures was
taken from the annual COLOSS questionnaire on honey bee colony losses. The most frequent activities were monitoring of
Varroa infestations, drone brood removal, various oxalic acid applications and formic acid applications. Correspondence
analysis and hierarchical clustering on principal components showed that six Varroa control options (not necessarily the most
used ones) signifcantly contribute to defning three distinctive clusters of countries in terms of Varroa control in Europe.
Cluster I (eight Western European countries) is characterized by use of amitraz strips. Cluster II comprises 15 countries from
Scandinavia, the Baltics, and Central-Southern Europe. This cluster is characterized by long-term formic acid treatments.
Cluster III is characterized by dominant usage of amitraz fumigation and formed by seven Eastern European countries. The
median number of diferent treatments applied per beekeeper was lowest in cluster III. Based on estimation of colony numbers
in included countries, we extrapolated the proportions of colonies treated with diferent methods in Europe. This suggests that
circa 62% of colonies in Europe are treated with amitraz, followed by oxalic acid for the next largest percentage of colonies.
We discuss possible factors determining the choice of Varroa control measures in the diferent clustersOpen access funding provided by University of Graz. The authors have no relevant financial or non-financial interests to disclose. COLOSS and its supporters had no influence on the study design or the decision to publish