NEW RESEARCH EXPLORES HOW FRIENDLY FUNGI COULD HELP FIGHT VARROA MITE

By Jessica Dempster

Researchers from Macquarie University are exploring how a naturally occurring fungi could help farmers fight Varroa mite, as the parasite continues to devastate Australia's wild and commercial bee populations.

Presented at the Australian Almond Conference in Adelaide this week, the research is examining the qualities and applications of Metarhizium - a naturally occurring fungi that can infect and kill Varroa mites while remaining safe for honeybees.

Chief investigator Associate Professor Fleur Ponton said the aim of the project - which is being conducted in partnership with Hort Innovation - is to develop a safe, affordable biological treatment for varroa that could serve as an alternative for current chemical measures being employed.

"Our goal is to develop a safe, affordable biological control that works with nature, not against it,” Associate Professor Ponton said.

Mass Fungi Plates from Varroa Mite Samples. IMAGE: Supplied (Macquarie University)

Postdoctoral fellow Dr Darsh Rathnayake said initial tests found the fungal strains killed high numbers of Varroa mites, with further testing now needed to identify the right concentration and determine whether the treatment can be used in commercial beekeeping.

“Our early results show that fungi could provide a promising new way to control Varroa mites, one of the biggest threats facing honeybees. In our initial tests, the fungal strains killed high numbers of Varroa mites,” Dr Rathnayake said.

“We are now working to identify a concentration that can effectively kill Varroa mites while remaining safe for honeybees.”

If successful, the newly developed treatment will offer beekeepers a safer, and sustainable form of hive protection.

Since arriving in Australia in 2022, varroa mite has spread and caused devastation to bee populations across New South Wales, Queensland, ACT, Victoria and South Australia.

An image of a Varroa mite (with scale) from the project. IMAGE: Supplied.

Varroa mite on a hive's brood frame. IMAGE: Supplied.

Current Varroa management relies heavily on chemical treatments, however some instances of chemical resistant Varroa have been detected across multiple states, highlighting the urgent need for alternative approaches.

The Varroa situation in Australia is putting immense pressure on the country's pollination system, with farmers/producers across various industires now having to consider and develop new pathways to ensure pollination of their crops

The pressure is particularly mounting for Australia's $1.3 billion almond sector, with Almond Board of Australia chief executive Tim Jackson saying pollination costs have risen since Varroa arrived.

"The almond industry has already experienced significant pollination cost increases since varroa arrived," he said.

"It is a slow-moving biosecurity trainwreck that requires immediate support to underpin the viability of beekeepers and pollination dependent industries. Around one in three things Australians eat need a bee to produce. The long-term ramifications cannot be understated."

Macquarie researchers engaging with bees as part of the project. IMAGE: Supplied.

Moving forward, researchers at Macquarie University's Research Centre for Pollination Futures will continue testing and refining the fungal treatment, aiming to develop an option that is effective against mites, safe for honeybees and commercially viable.

Associate Professor Ponton said healthy honeybees are fundamental to fundamental to food production, making it essential to develop sustainable approaches to Varroa management that will help combat the pest in the years to come.

“Healthy honeybees are fundamental to so much of our agricultural system. We need to be thinking now about what sustainable varroa management looks like in five, 10 and 20 years’ time," she said.