Francis Ratnieks recalls a recent trip to California and looks at the focus on natural resistance to honey bee diseases.
In December 2016, in the Marconi Conference Centre in Marshall, California, I attended a very unusual conference on bees, called Bee Audacious. There were about 100 of us, all with some interest in bees or helping bees. Unlike most conferences there were no formal talks. Instead the meeting was based on dialogue, in which we met in small groups to discuss a range of topics concerning bees. I had been asked to be one of the 10 Thought Leaders (8 bee scientists and 2 commercial beekeepers).
Throughout the meeting the ideas of the participants were noted and will soon result in a report by Professor Mark Winston of Simon Fraser University, Vancouver, Canada. Mark was one of the main instigators of Bee Audacious. For many years he was a honey bee scientist at SFU but is now the Academic Director of SFU’s Centre for Dialogue, while still remaining a Professor of Biological Sciences and maintaining his interest in bees.
On 12 December 2016, a day after the meeting ended, there was a public meeting at Dominican University in San Rafael in which each of the Thought Leaders gave a short talk, followed by questions, reporting on the discussions at Bee Audacious. The interactions I had at BA, both in and out of the sessions, reinforced my feeling that beekeepers are now ready to place greater emphasis on using natural resistance to combat bee diseases and to reduce reliance on synthetic chemicals such as antibiotics, which are widely used in the USA but not in the UK, and acaricide strips. So this is what I covered in my talk. If anyone would like to hear what we said all the talks are on You Tube at the link below. My talk begins at about 24 minutes and 30 seconds.
For me, one important source of reinforcement were comments made by several commercial beekeepers who were clearly worried that current synthetic chemical treatments of varroa were not working well due to resistance, and would work less well in the future. I also understood better the challenges that commercial beekeepers face. Their livelihoods depend on their bees, and many of them also employ other people and feel a great responsibility. One of the beekeepers at BA had 30,000 hives and employs 30 people.
Additional sources of reinforcement came from the comments of many beekeepers, including smaller scale beekeepers, who wanted to carry out beekeeping without synthetic chemicals, and from the interest shown in the discussion session on “Diseases and pests: what are the next generation of controls?” It was popular and many participants were interested in non-chemical controls.
Outside the sessions I also spoke to people who were keeping hives in isolated regions without the use of chemical controls and scientists who were studying isolated populations of honey bees that were surviving despite not receiving any disease management from beekeepers. Their comments and perspectives indicate that natural selection can also result in honey bee colonies that have high levels of survival without the use of synthetic chemicals to treat diseases, and which also show natural resistance to diseases such as via high levels of hygienic behaviour.
It seems, therefore, that both bee breeding, such as we are doing at LASI with hygienic behaviour and LASI Queen Bees, and natural selection are probably both doing the same thing: improving the natural ability of honey bee colonies to resist diseases. This made me think that perhaps now is the right time to increase the use of natural resistance in the control of honey bee pests and diseases, possibly aided with some “soft” chemicals such as oxalic acid to help in the control of varroa, as resistance of the varroa to these chemicals is unlikely. Natural resistance mechanisms include hygienic behaviour and grooming.
What have beekeepers got to lose by using natural resistance? Specially in the USA but also in the UK and Europe, they are already losing a large proportion of colonies each year even while using synthetic chemicals as these are not always very effective at controlling diseases and pests (e.g., varroa) and can be harmful to the bees (e.g. Amitraz, which is widely used in the USA). In addition, several important diseases (e.g., chalk brood, deformed wing virus) have no chemical controls but can be controlled by hygienic behaviour. More generally, where does pest and disease control with synthetic chemicals lead? Ultimately, it leads to chemical resistance in the pest or pathogen, which means that control is only temporary. It does not lead to pest and disease resistance in the bees, which is something that would be of lasting benefit.