A comment by the lovely Amelia from afrenchgarden.wordpress.com on my last post led me to look at the University of Sussex’s Laboratory of Apiculture and Social Insects (LASI) website.
I was dismayed to see a new press release, ‘Scientists determine how to control parasite without harming bees‘, which advises beekeepers not to use the trickling or spraying oxalic acid method (which is what most beekeepers I know use). Instead sublimation (also known as vaporisation) is recommended.
“Professor Francis Ratnieks, head of LASI, says that beekeepers should cease using the other two methods (“trickling” and “spraying”, in which a solution of oxalic acid is used) as they are harmful to the bees and less effective at killing Varroa.”
Research accompanying the press release was due to be published today (Tuesday 5 January 2016) in the Journal of Apicultural Research, but unfortunately this journal is not publicly accessible to non-subscribers. I’ll try to see if I can access it through work as I would like to read the research study – it’s called ‘Towards integrated control of varroa: comparing application methods and doses of oxalic acid on the mortality of phoretic Varroa destructor mites and their honey bee hosts’ by Hasan Al Toufailia, Luciano Scandian and Francis Ratnieks.
The press release says the trickling and spraying methods “cause harm to bee colonies, resulting in reduced winter survival”. I wonder why harm is caused, how great the harm is, and whether it outweighs the harm caused by not treating for varroa at all. Emma and I have never had any colony losses following oxalic acid trickling and I cannot recall other beekeepers having experienced this either, but perhaps LASI have found colonies to be weakened by it afterwards.
Hopefully Beecraft and BBKA News will mention the study in their February issues.
EDIT 29/02/16: The research has now been published and I’m grateful to the Journal of Apicultural Research for generously making it freely available to the public: Towards integrated control of varroa