During the winter of 2014/2015, in Poland, honey bee colony losses were again high
Warsaw University of Life Sciences, Faculty of Veterinary Medicine, Department of Pathology and Veterinary Diagnostics Sciences, Laboratory of Bee Diseases
In Poland, in 2015, the survey of winter honey bee colony losses was based on the stratified randomised sampling done in 2014, so the COLOSS questionnaire was sent to the same beekeepers as in the previous year. Additional new beekeepers replaced those who, after 2014, were removed from our list for various reasons (beekeeper died, apiary closed down, wrong address).
At the beginning of April 2015, 1552 questionnaires (together with envelopes with return address and stamps) were posted to beekeepers.
By the end of June we received 469 filled in questionnaires and 94 return letters with questionnaires which, for various reasons, had not been delivered to the recipients. At the beginning of June we posted 94 letters to new randomly selected addresses and 989 reminders to nonresponders. By July 15th we received 717 filled in questionnaires in total.
The analysis of the data showed that the losses experienced by beekeepers, although low in the previous winter (7.7%), this winter were high again and reached 16.3% (overal proportion of colonies lost). The highest losses were in Kuyavian-Pomeranian province (27.8%) and in Lesser Poland (27.5%). In four other of the sixteen Polish provinces (Lower Silesian, Lubusz, Greater Poland, Opole) the losses exceeded 20% The lowest losses were in Subcarpathia 9.8%) and West-Pomerania (10.2%). Generally the losses were the highest in the south-western regions of the country. Losses resulting from unsolvable problems with queens, revealed after winter, reached 3.6% and were a bit higher than reported in Europe (about 3.0%). The average loss experienced by Polish beekeepers was 19.4%. Unexpectedly, there were much fewer beekeepers reporting losses between 10% and 20% (152) than beekeepers reporting lower and higher losses (331 and 230 respectively). As in previous years beekeepers whose bees foraged on maize lost many more colonies than beekeepers who claimed that their bees did not have access to such plantations (20.6% and 15.5% respectively). However, in comparison to the beekeeping season of 2014, in 2015 fewer beekeepers (15% and 7.8% respectively) noticed in their apiaries symptoms which could suggest bee poisoning (the answer to the additional question in the COLOSS questionnaire). In the face of the ban on using neonicotinoids for protection of plants utilised by bees, these last results could be a contribution to the discussion on the role of neonicotinoids in summer and winter bee losses.