The Australian government body in charge of pest control has announced the country will abandon efforts to eradicate the varroa mite.
This parasitic mite lives in honeybee colonies, feeding on pupae and adult bees. The mites spread viruses, impair the bees’ ability to fly or communicate and makes them more susceptible to pesticides, eventually causing a colony collapse if left unmanaged.
Until recently, Australia remained free of varroa thanks to stringent biosecurity measures. But in June 2022, the mite was detected in the New South Wales coastal area near Newcastle in the southeastern part of the country. It has continued to spread since.
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A recent increase in detections over a greater area has now made eradication technically unfeasible. As a result, Australia is transitioning from eradication to management of the varroa mite.
It has been a tough time for beekeepers, the broader beekeeping community and the growers of crops relying on honeybees for pollination. Varroa mite is already causing significant economic damage to livelihoods, due to restrictions on hive movements and the euthanasia of around 30,000 bee colonies.
To manage it, Australians will need to learn from overseas, where people have lived with varroa for decades. However, Australia must also develop its own solutions in line with its unique climate, biodiversity and agricultural systems.
As seen in other countries, honey production and hive numbers may remain relatively stable. But beekeepers will need to invest significant time and resources to monitor, manage and replace hives due to varroa losses.
There are effective chemical control options, but these cannot eliminate the mites completely. They also have impacts on bees and can leave residues in hive products. Over-reliance on synthetic chemicals will rapidly lead to resistance in varroa populations, as seen in almost every country where the mite exists.
Effective organic and non-chemical treatments exist, but they are comparatively labour intensive – an additional burden on certified organic beekeepers.
To keep mite numbers below economically damaging thresholds, beekeepers will need to use integrated pest management solutions, a combination of approaches to reduce mite populations and producer following-up to ensure these approaches have done their jobs.
Costs for the average-sized Australian bee business could increase by as much as 30 per cent. Experience in other countries suggests there will be significant declines (up to half) of hobbyist and semi-commercial operators. Currently, recreational beekeeping is worth A$173 million (C$150 million) annually.
It is estimated that varroa will progressively kill around 95 per cent of Australia’s feral honeybees within approximately three years. Therefore, we will likely need more bee colonies per hectare to pollinate some crops effectively.
Cumulatively, increased costs of production, a decrease in the numbers of beekeepers and fewer feral bees will likely result in higher demand for beehives to service 35 pollination-dependent industries across the country.
As seen in Aotearoa, New Zealand, where the varroa mite established in 2000, the price for beehives rented to growers increased by 30–100 per cent per hive within five years.
We need a national program in Australia that monitors colony losses so we can quantify the impacts across the sector. This also holds true for Australian native bees, which play an important role in pollination of tropical crops.
We do not have the monitoring and baseline data needed to evaluate the changes about to occur.
As an industry that contributes more than A$14.2 billion to the Australian economy, there is a critical need for national capacity building for beekeeping, varroa and pollination research, industry development and training.
Western Australia and Tasmania have significant opportunities to remain free from varroa for as long as possible. The mite is currently only in New South Wales on the eastern border. Restricted movements of honeybees across the Bass Strait and the Nullarbor Plain offer an additional biosecurity buffer.
Australia also remains free from virulent bee viruses, such as the deformed wing virus. Hopefully, the varroa incursion will lead to strengthened biosecurity for honeybee pests and diseases we do not have in the country yet.
We also need to strengthen compliance with the honeybee biosecurity code of practice and improve monitoring of bee losses, bee viruses and native bees.
In the long term, we will need to establish breeding programs for bees with varroa tolerance, as seen in other global regions such as the United States and New Zealand.
– This article first appeared in the Conversation, by Reuters.
