How smart sensors could help honeybees resist varroa mites

There are 168 exotic invasive species identified as key threats to Australia’s environment and biodiversity.

One of them is the varroa mite which feeds on honeybees and transmits bee viruses.

This mite has the potential to severely affect honey production and a wide range of pollination-reliant food crops and crops that support primary food production.

Varroa mite was first detected in Australia in New South Wales in 2022 and is now widespread across the state.

Professor Sasha Mikheyev with a stingless male honey bee (a drone) collected for genetic research into Varroa resistance. Credit: Nic Vevers/ANU

Professor Sasha Mikheyev from the Australian National University’s Bee Lab is attempting to urgently stem the research gap in the fight against the varroa mite, by collecting pre-varroa bee data to understand how varroa resistance evolves.

The aim of the data is to eventually breed varroa-resistant genes into commercial bee stock.

Tell us about your background. How did you become a bee researcher?

My grandfather was a hobby beekeeper, and I was always fascinated by the industriousness of these tiny creatures. The more I learned about bees, the more fascinating they became. After over a decade of working with ants and other creatures, such as snakes, I returned to studying honeybees, realising that they are a fantastic model system for studying host and pathogen coevolution, lying at the nexus of scientific inquiry with real-world consequences.

What are varroa mites, and why are they a problem?

Varroa mites are tiny parasites that infect bees. If a bee were scaled up to our size, a mite would be roughly the diameter of a dinner plate. These mites feed on developing pupae and transmit viruses that ultimately lead to colony mortality. A worldwide epidemic of varroa has been ongoing for about 70 years, with Australia being the last continent to be colonised. We expect that the mites will decimate Australia’s feral bees and change how beekeeping is done once varroa spreads nationwide in the next few years.

What are varroa-resistant bees, and where can we find them?

Some honeybees are naturally resistant to varroa. For example, African honeybees seem to have no problem, though they are very aggressive and don’t represent a good solution. Intriguingly, some feral bee populations also evolve resistance when challenged by the mites, but we don’t know the mechanisms of this resistance, making it hard to harness in an applied context.

A major focus of my research is to use Australia’s unique position to collect pre-varroa bee data to understand how varroa resistance evolves. Once we understand this, we can hopefully help bees by breeding resistant genes into commercial stock. Importantly, native bees are also fully varroa-resistant because the mites are very host-specific and native bees are unrelated. Potentially, native bees could replace managed honeybees in some pollination contexts.

Why do you want people to collect bees?

We want to follow the decline and recovery of bee populations as varroa spreads. Amazingly, this hasn’t really been done elsewhere. Our ability to do this in Australia is also rapidly closing. However, the scale of Australia is immense, making it impossible for one team to survey it alone.

Taking a cue from the bees, we can band together, and all participate in collecting data. The data collected over time will show us how bee populations are changing and help identify regions of the genome under selection, as well as provide a wealth of other data, like the evolution of varroa and the viruses they carry.

Where can we find more information and get involved in this important citizen science?

There is an article about our citizen science project on the ANU College of Science website. We haven’t started recruiting participants in earnest as we need funds for a full-time network manager. However, we hope to have a PhD student starting soon and might aim to launch a limited network around New South Wales later this year.

Professor Mikheyev capturing drones using a queen pheromone bait which is tied to a helium balloon suspended from fishing line. Credit: Nic Vevers/ANU

There are many smart sensors being put into beehives (temperature, humidity, sound) to help the industry. How can they help you conduct this important research? Or what sensing data would you wish for?

I think there’s good potential for combining smart sensors with trapping feral bees for future research and breeding. One way to do this is to set up bait boxes for bee swarms to colonize. However, these boxes need to go into remote places and visiting them is time-consuming. If such a trap can identify and signal that a swarm has moved in, we will retrieve it.

If you have any biosecurity challenges or have an idea for an environmental or agricultural smart sensing project, contact NSSSN Environment & Agriculture Theme Leader Dr Tomonori Hu on tomonori.hu@nssn.org.au.