Here’s how beekeepers and the DPI are trying to stay ahead of the MNC’s deadly varroa mite parasite

NSW has given up on trying to eradicate varroa mite – the greatest biological threat to Australia’s honey bee and pollination-dependent plant industries – and instead is focusing on long-term management.

It’s been more than two years since varroa mite spread to the Mid North Coast. Since then, some local beekeepers have left the industry, while others continue to be challenged by parasitic mites that attack European honey bees and can kill entire colonies.

It remains unknown how many beekeeping businesses have shut up shop since varroa mite entered Australia – a national survey is being conducted. In the meantime, as spring sets in, warm weather increases the chance of varroa mite production and re-infestation of hives.

🛑 Eradication attempts abandoned

When varroa mite was first detected in the country, in June 2022, the infestation was considered feasible to eradicate and affected hives were euthanised.

After 14-months of destroying mite infected hives with fuel-soaked rags, attempts to eradicate varroa mite were abandoned in September 2023.

The Department of Primary Industries (DPI) told the Mid North Coaster that by the time it shifted from eradication to management of varroa mite, the emergency response team in NSW had conducted surveillance on more than 30,000 hives.

Nationally, $101 million was spent during the eradication response.

📋 Managing the deadly mite

In March, the number of Bee Biosecurity Officers (BBO) were doubled to six full-time positions, to provide more support to beekeepers in managing varroa mite.

Over the past 16 months, the National Varroa Mite Management Program (NVMMP) has held 121 workshops nationally to provide information on how to manage varroa mite,  including chemical control. 

There are seven chemical products approved for controlling varroa in Australia. To kill the mite, some target the nervous system and others the respiratory system.

Still, local beekeepers are looking for other options. Some are turning to heat treatment as a non-chemical approach.

🐝 Bee and honey health

The NVMMP states all chemical control products for varroa management can have negative effects on honey bee health – the main reason Mid North Coaster beekeepers Ana Martin and Sven Stephan opt for heat techniques.

“From the beginning, we never put any chemicals in our hives,” Stephan told the Mid North Coaster. “We’d rather give up beekeeping”.

Martin and Sven were introduced to Varroa Controller – a machine that heats to a temperature that is safe for the colony, but lethal to the mites. They ended up bringing the machine from Austria to Australia to sell.

They believe the chemical-free approach is safer for bees and better for honey cleanliness, and that the varroa mite cannot become resistant to the treatment.

The DPI insists its approved chemicals are effective and safe when rotated correctly. 

🚫 Risk of resistance

A DPI spokesperson said the NVMMP had not received any evidence that varroa mites in Australia were resistant to any of the products approved for use.

However, according to DPI, in the UK, Europe and the US, some treatments are now ineffective due to varroa becoming resistant following prolonged misuse. This can include  repeated use of the same chemical control product and leaving products in the hive for shorter or longer than the specified treatment time.

The NVMMP recommends all beekeepers adopt an Integrated Pest Management (IPM) approach to managing the mite. IPM encourages the use of non-chemical controls first, known as cultural and mechanical controls, in order to minimise chemical use – and the risk of residue and varroa developing chemical resistance.  

The DPI states when a Varroa threshold is met chemical control is required to ensure colony survival. 

Cultural control includes breeding for varroa-resistance traits and brood interruption such as caging the queen bee, and mechanical controls include brood trapping using drones.

🍯 Clean honey concerns

As for the honey, according to DPI the Australian Pesticides and Veterinary Medicines Authority performs detailed risk assessments before approving a chemical product for use in food production. Treatments that do not result in clean honey are not approved.

However, Stephan and Martin will continue to avoid chemical use to control varroa mite in their hives.

“The idea is that you can raise healthy colonies, control the mite, and not have any chemical in your honey and chemical load on the bees that is not good for them either,” Martin said. 

In spring and summer, it is not uncommon for hives to be reinfested in areas of high mite loads within weeks following treatment.

The Honey Bee Colony Loss Survey is taking submissions until November 1, 2025. It is led by researchers and representatives from the Australian Honey Bee Industry. The results will provide insights into hive losses and varroa impacts across the country.

For more information: varroa.org.au

Thumbnail: (L) Sven Stephan and hives, supplied by Ana Martin (R) European honey bees, Unsplash.