What is Varroa mite and why should we bee worried?

The varroa mite is the world's most devastating honey bee pest. Varroa mites are external parasites, about the size of a pinhead, that attach to the body of bees and weaken it by feeding on the haemolymph (insect version of blood), and also feeds on larvae and pupae.

Along with slowly killing bees and decreasing populations, mite is a vector for at least five debilitating bee viruses, including the deformed wing virus.

As the infestation builds up, the parasite causes scattered brood (eggs, larvae and pupae), crippled and crawling honey bees, impaired flight performance, a lower rate of return to the colony after foraging and a reduced lifespan for bees.

This ultimately causes a reduction in the honey bee population, stops the replacement of queen bees and eventual colony breakdown and death.

There are no effective natural enemies of varroa mite.

Varroa mite has decimated honey bee populations around the world, but Australia is the only continent and major honey producing nation not to have the mite.

The mite has widespread ramifications for the environment and agricultural industry, which rely on the pollination service of both controlled and feral honey bees.

The total contribution of honeybees to Australia's economy is estimated at $14.2 billion, with 35 agricultural industries in Australia relying entirely or in part on bee pollination, including almonds, apples and cherries.

Every year, billions of bees are moved around the country to help pollinate crops. Almond pollination - which is 100 per cent reliant on bees - is around the corner, due to start when the trees blossom in the last three weeks of August. However, the industry is already predicting losses, as a biosecurity standstill order prevents bees moving from or through NSW.

The increased cost of pollination services would be passed onto the consumer, increasing the price for about a third of the food we eat.

The honeybee industry itself is forecast to take a $70m hit from a widespread outbreak.

In the United States and Europe, Varroa mite destroyed 95 to 100 per cent of uncontrolled bee populations. The mite breached New Zealand's border in 2000 and wiped out 98 per cent of feral bees hives.

Green thumbs across the nation would also feel the effects. Without wild European honey bee populations, backyard fruit trees and veggie patches are much less likely to be pollinated.

Native bees (which are not affected by the mite) and other insects do provide pollination services, but nowhere near enough to make up for the loss of European honey bees.

In short, with great difficulty. No country has successfully eradicated the mite once it's become established, but it is possible if swift action is taken before it takes hold.

Within Australia's agriculture and biosecurity circles, a varroa mite incursion has long been considered a case of 'when' not 'if', and the nation has prepared accordingly.

The NSW government has enacted a multi-layered containment and eradication strategy.

A 50km biosecurity zone was established around the Port of Newcastle, where it was first detected, and beekeepers within that area must also notify the NSW Department of Primary Industries of the locations of their hives.

Within that 50km zone, a 25km surveillance zone was set up, where officials are monitoring and inspecting both managed and feral honey bees to limit the extent of the incursion.

Beekeepers are urged to do "sugar shakes" on their hives, which involves placing the bees in a jar and rolling them in sugar, which loosens the grip of the mite and dislodges it, and report any detections to the DPI.

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All bee hives within a 10km radius of the infected hives - the third and final emergency zone - will be eradicated, regardless of whether the mite is present.

Another biosecurity circle was set up on the Mid-North Coast, after an infestation was found in Bulahdelah on Wednesday.

So far, more than 600 hives have been destroyed - including 120 outside the biosecurity zone at Trangie in central northern NSW - and that number will grow.

Bees are generally euthanised by pouring petrol into the hives, leaving it overnight and then setting it on fire.

The NSW government will look to release chemicals via a baiting system within the eradication zone to nullify feral bee populations, which are considered a real risk given their locations and movements are unknown.

In previous Queensland incursions (more information on that below) a number of surveillance methods were used, including aerial balloons that attract male Asian honey bees with a queen pheromone trap, sweep netting of flowering plants that are visited by the bees and setting up feeding stations to attract foraging bees.

Despite the potentially national significance of an uncontrolled outbreak, it's the NSW government leading the response.

Keeping biosecurity threats out of the country is the jurisdiction of the federal government, but once those threats breach the border, responsibility falls to the state governments.

At the moment, the government isn't sure how it got in. Given it was first discovered in sentinel hives - dummy or surveillance hives, set up with the sole purpose of detecting exotic pest incursions - at the Port of Newcastle it likely hitched a ride on a ship or container.

There have been two previous Varroa mite incursions in Townsville, in 2016 and 2019. They were believed to have hitchhiked in an Asian honey bee net on a shipping container from Papua New Guinea (PNG) or the Solomon Islands.

Both times it was successfully eradicated. However, the Townsville incursions were Varroa jacobsoni, a species of Varroa mite that generally targets Asian honey bees (which are found in north Queensland and considered a pest) and does not readily move to European honey bees.

The Newcastle incursion is Varroa destructor, which is the mite that has spread around the world with devastating consequences for European honey bees.

There is a state government compensation framework in place for beekeepers forced to destroy hives, which uses a formula based on lost income, honey and equipment. The government is currently working with the industry to determine the market value of equipment, but wants payments made as quickly as possible.

At this stage, no compensation is on offer for recreational apiarists, but Australian Bee Honey Council chair Steve Target said the industry wanted both commercial and recreational beekeepers to receive compensation.

"If we beat this incursion, we need these recreational beekeepers on side for the next incursion to do the right thing," Mr Target said.

"If they don't get compensation this time, they'll say 'well I'm moving my bees out of here because I lost them last time'. We need to work as a team."

In the short term, no. The past two seasons have been kind to apiarists and there is plenty of Australian honey in stock.

"With all the rain we've had the season ahead looks quite good as well," Mr Target said.

However if the outbreak is not controlled, it could cause a shortage of Australian honey and would definitely drive up the cost, as beekeepers face hire input and monitoring costs.