The colonies were started as package bees or nuclei and initially treated against V. destructor, ensuring uniform starting conditions in terms of strength and infestation level of all colonies within each location. Queens were produced either by the partner institutes or commercial partners and delivered by hand or express mail to the allocated partners. Queen introduction was completed on 1 October 2009 which was therefore defined as starting date for the survival test.
The colonies were managed by the partner institutes according to a standardised common protocol until 31 March 2012 and were not further treated with chemical substances for the control of V. destructor or other diseases. Colony and queen survival were recorded at least three times a year (in spring, summer and autumn) together with other traits and parameters.
When colonies collapsed, the presumed cause of death was noted and classified based on analysis of previously collected samples and / or easily detectable symptoms. The classes were: varroa, nosema, queen causes (queenlessness, drone laying queen, swarming without successful queen replacement, etc.), other (like American foulbrood, weakness, starvation, winter loss, robbing, apitechnical reasons), and unknown.