The 20 hives set up at INRA are also being continuously monitored for health conditions including Varroa destructor infestation (using the icing sugar method), the presence of chalkbrood (Ascosphaera apis) and Nosema ceranae.
In addition regular estimates of the number of bees and amount of brood are being made. Vibration data has been collected for more than 100 days in the form of averaged spectra from the accelerometers.
Principal component analysis (PCA) has been applied to these data and a high level of similarity has been obtained from hive to hive for the healthy colonies.
All but one of the colonies at INRA were lost over the winter of 2013/2014, however, this has provided valuable data showing how the vibrational signals change as a colony is lost.
All colonies that had been lost over the winter were repopulated in advance of the 2014 swarming season.