What are varroa mites and should we bee afraid?

The invasive parasite was most recently detected in the New England region, where the NSW Department of Primary Industries (DPI) discovered an infested hive that was relocated from Kempsey to Tamworth.

But, the question you maybe asking is, what are varroa mites and what risk do they really pose?

The sneaky varroa mite - also known as varroa destroyer- are tiny red or brown parasites that latch onto a honey bee and suck the life out of them.

The mite does so by feeding off the bees larvae or pupae.

"They particularly attack drone bees," Charles Sturt University, associate professor of entomology, Doctor Paul Weston said.

"In a colony, there are tens of thousands of worker bees, one queen bee, and then drone bees. The drone bees are mainly male and their main purpose is to inseminate the queen."

These mites will not only feed off the larvae, but can also spread honeybee viruses, cause a bee to malfunction, and if the mites are left unchecked can kill off entire colonies.

"They will feed on the larvae and lay their owns eggs. But, this is only a fraction of the colony, but the mites do so to weaken the colony," he said.

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The very first detected case of varroa mites in Australia was detected in a sentinel beehives, in the Port of Newcastle, on June 2022.

A sentinel hive are closely monitored hives that are set-up for the early detection of invasive species, such as varroa mites.

After the discovery, a 10km eradication (red) zone and a 25km surveillance (purple) zone were put in place, meaning hives could not be moved into, within or out of those affected areas.

"It was found and the NSW Institute of primary industries set up a 10-kilometre eradication zone and then the whole state was put under emergency," Dr Weston said.

"Any bees in that zone were destroyed, also the beehives. Then throughout the year after that there were other incursions that were found, reasonably close to Newcastle."

Since then, the mites have continued to spread throughout regional NSW and even reached towns situated on the border between NSW and Victoria.

In total, the NSW DPI has found a total of 236 infested premises, tested more than 130,000 hives across the state, and has destroyed 28,000 hives.

The reason for the DPI's eradication of infested bees and their hives is because without the bees varroa mites are unable to reproduce.

Dr Weston said bees are quite mobile creatures and through that, the mite can spread.

"They do not tend to disperse, because they are colonial; they form colonies. Bees' may forage several kilometres from where their hive is, but they will come back, after foraging for nectar and pollen,"

"The only time we see disposal further is when a hive undergoes a swarm, which is a natural occurrence in the spring. If the number of bees in the colony gets high, and there are two queens, a portion of the hive will branch off and start a new colony."

Bee's are a critical part of the circle of life, as they pollinate every plant that will go on to support our ecosystem and our food chain.

According to the Department of Agriculture, Fisheries, and forestry the beekeeping industry is worth more than $14 billion dollars, with commercial bee keeps producing 37,000 tonnes of honey annually.

The NSW DPI confirming this is the biggest biodiversity response in Australia's history, aside from COVID.

Dr Weston said the immediate effect of varroa mites is on the beekeepers in the emergency zone.

"They will face loss of their bees and their beehives, which means they will be a sustainable cost to re-establish their colonies. But, they can't do that yet, because varroa mites are present," he said.

The NSW government in early July announced $30 million dollars of funding to support the eradication of varroa mites.

"There will be an increase costs in managing varroa mites, but in countries such as New Zealand when they became infested is they are placing miticide strips in beehives, that are filled with chemicals that impact mites, but not the bees," Dr Weston said.

Dr Weston said in terms of cost and time there will be an effect, but it will not cripple the industry.