NEW research shows crops such as apples that rely heavily on bees for pollination could be affected if varroa mite reaches Australia.
The research shows Australian honeybees are highly susceptible to the pest, which will potentially devastate them if it reaches the country.
The exotic varroa mite (varroa destructor) is present in all beekeeping countries worldwide except Australia.
The size of a sesame seed, varroa mites attach themselves to bees and suck their blood, leaving them more susceptible to disease.
Where varroa is present it devastates beehives and requires intensive treatment with miticides to control it.
A research project carried out jointly by the University of Sydney and the United States Department of Agriculture Agricultural Research Service and funded by the Rural Industries Research and Development Corporation (RIRDC) evaluated seven lines of Australian bees and found none had any resistance to the varroa mite.
The research confirmed an incursion of the pest would have devastating effects on bee populations and those industries that rely on them for pollination.
The research project compared the responses of the Australian honeybees to a varroa infestation with the responses of US Italian honeybees that are known to be susceptible to the mite and two other types of honeybee known for their resistance to varroa.
After only four months of exposure to the varroa mite 44 per cent of all the Australian honeybee lines had died.
This compared to a 4 per cent mortality rate over the same period for the most resistant Russian honeybee, which isn't found in Australia.
Professor Ben Oldroyd of the University of Sydney said the research provides a clearer picture on the potential impacts of a varroa incursion in Australia.
"It is largely accepted that varroa will eventually reach Australia and the findings from our research give us an indication of just how severe an impact this pest will have on our honeybee populations," Professor Oldroyd said.
"If the Australian honeybee industry and honeybee dependent crops are to have any chance of minimising the impact of varroa when it arrives then it is critical varroa-resistant honeybees are bred for the Australian environment and urgently."
