A SWARM of Asian honeybees carrying varroa mites has been detected and destroyed in Sydney.
More than 2000 of the bees were discovered on a ship at Kurnell after the Singaporean bulk vessel had been identified by a DAFF inspection.
Department of Agriculture, Fisheries and Forestry Biosecurity said there were more than 150 of the destructive varroa mites attached to the bees.
Australian Honey Bee Industry Council quarantine committee chair Trevor Weatherhead said a varroa incursion would devastate his industry.
"If these bees had made it to the mainland I'm confident it would have affected our live export of bees to places like Canada," Mr Weatherhead said.
"This type of mite, the Jacobsoni varroa, wasn't always a threat to bees but has now been seen to reproduce on European honeybees in New Guinea.
"Similarly, in the Solomon Islands, Asian honeybees have been shown to outcompete European honeybees.
"This is a problem because Australian agriculture relies on the European honeybees for pollination," he said.
Mr Weatherhead said only one or two bees had been intercepted at the ports in the past 10 to 15 years.
DAFF's border compliance division spokesman Tim Chapman said a DAFF beekeeper bagged and treated the swarm without any bees escaping.
"DAFF's biosecurity officers completed the inspection with the assistance of the beekeeper and pest controller and continued surveillance of the vessel overnight," Mr Chapman said.
He said the Jacobsoni variety of varroa mite found on the vessel wasn't the more destructive of the species.
A DAFF spokesman said every international vessel arriving in Australia had to be cleared by DAFF biosecurity.
"DAFF conducted more than 12,000 vessel inspections in 2011-12," he said.