The afternoon sun cuts through a stand of eucalyptus at a Hunter Valley apiary as a beekeeper tilts a frame towards the light. Scattered across the capped brood, pepper-sized and reddish-brown, sit the mites she has spent four years dreading. Varroa destructor has arrived in force, and the inspection she is running is less a survey than a count of what is left.
For the roughly 25,000 registered beekeepers managing more than 670,000 hives across Australia, that scene is becoming routine [1]. The external parasitic mite that feeds on developing bee pupae and adult workers has slipped past the country's biosecurity defences and is now established in New South Wales, with detections in other mainland states including Victoria. Once it infests an unmanaged colony in a temperate climate, that colony typically collapses within two to three years [2]. The economic threshold for treatment is reached when roughly 3 per cent of bees in a hive carry the mite [2]. Beyond that line, the colony is functionally doomed without intervention.
The mite and the colony
Varroa's biology explains why it is so destructive. Female mites enter brood cells just before they are capped and reproduce beneath the wax, feeding on the developing bee. The wounds they leave weaken adults, deform wings and shorten lifespans. More consequentially, varroa vectors at least five and possibly up to 18 bee viruses, including Deformed Wing Virus, the most damaging of those viruses [2]. Deformed Wing Virus was not present in Australian honey bees before the mite arrived. Roberts, Anderson and Durr demonstrated in 2017 that Australia was uniquely free of both the mite and DWV, offering the world a rare control site for studying viral dynamics in honey bees [3]. That comparative advantage has now been spent.
The incursion and the failure of containment
The index case is dated to June 2022, when varroa was detected near the port of Newcastle in New South Wales, the conventional explanation being that the parasite arrived on a ship or in imported bees [1]. Within months it had been confirmed at more than a hundred sites, far beyond the original red eradication zone [4]. By the end of that year authorities had destroyed more than 17,000 hives to slow the spread, although fewer than 1 per cent of those hives actually carried varroa [1]. The destruction included 250 colonies at Tocal Agricultural College, while 48 high-value queen bees from the Plan Bee national genetic improvement program were removed and rehomed. The loss of breeding lines from the disruption will take years to recover from.
Containment was undermined by a familiar problem: beekeepers moved hives out of the eradication zone into the surveillance or purple zone, which became a reservoir for reinfestation [1]. A peer-reviewed spatial analysis by Mshelbwala and colleagues, published in 2025, confirmed the pattern, finding that environmental and management factors were significant predictors of varroa detection across New South Wales [5]. The official posture has now shifted. Australia is no longer attempting to eradicate varroa. It is managing it, like every other major beekeeping country in the world [6][7].
The pollination economy under pressure
The size of the stakes becomes clearer once pollination is put in dollar terms. Australian government and industry estimates place the value of pollination services to agriculture somewhere between A$8 billion and A$19 billion a year, with the variation reflecting what is counted: commercial honey bees alone, or commercial bees plus feral honey bees, plus native bees and other nectar-loving insects [1]. The combined contribution of all of those pollinators has been put at roughly A$14 billion, a figure drawn from assessments of the 2019-20 bushfire season, which killed enormous numbers of managed, feral and native bees and briefly exposed how thin the margin really was [1].
Honey itself is a much smaller industry. Australia produces around 30,000 tonnes of honey each year, worth approximately A$90 million, a useful anchor for understanding just how disproportionate the value of pollination is compared to the value of the hive product [1]. Once varroa becomes endemic, the commercial beekeeping sector faces structural contraction. Whitehouse and colleagues, writing in Current Opinion in Insect Science in 2025, argue that management must be tailored to the phase of infestation, with the chronic, low-level phase of an established outbreak requiring different tools than the acute phase that follows first detection [8]. They also note that miticide resistance is now a serious and growing global problem, with multi-acaricide-resistant populations documented in multiple countries [8]. For Australian beekeepers who have never had to treat for varroa at all, that learning curve is steep and expensive.
Horticulture will feel the squeeze first in almonds. Australia's almond industry is the most pollination-dependent horticulture sector by a wide margin, and contracts large volumes of hives for the late-winter pollination season. Avocados, apples, cherries, pears and stone fruit follow, and the brokers who coordinate pollination contracts are already warning growers that hive prices will rise and supply will tighten. If commercial hives are diverted into treatment, recovery and breeding, fewer are available for paid pollination. The 2019-20 bushfires offered a partial preview: hundreds of hives were lost, native pollinator habitat was incinerated, and pollination contracts became difficult to fulfil in some regions for several seasons.
The feral collapse nobody saw
What is less discussed, and what may matter most in the long run, is the impending loss of feral honey bees. Until the mite arrived, Australia carried a large, healthy population of unmanaged Apis mellifera living in tree hollows, roof spaces and bushland. Because they were never treated and never inspected, they have been quietly pollinating a great deal of native flora, pasture and horticultural crops that were not part of any paid pollination contract. Chapman and colleagues, in a 2023 review in Biology Letters, forecast the near-complete removal of unmanaged honey bees in Australia as varroa becomes established [4]. Their work makes clear that the impact of varroa on both natural and agricultural systems is driven less by what happens to managed hives than by what happens to the feral population that has been pollinating in the background.
The shift will not be uniform. Some areas may see a partial transition to pollination by native bees, particularly the several thousand species of Australian native bee, some of which are known to pollinate commercial crops including macadamias. But the density of native bees is generally lower than the density of feral honey bees, and many native species are themselves under pressure from habitat loss, climate variability and, in some regions, repeated bushfire. The feral collapse is, in effect, a quiet, distributed loss of a workforce that nobody was paying for and almost nobody was tracking.
What is being tried, and the limits of each
The tool kit available to Australian beekeepers is well understood overseas, if under-used here. Chemical miticides remain the first line of defence, and Sattler and colleagues, in the first national survey of Australian beekeeper attitudes published in Ambio in 2026, found that most respondents still rely on them [9]. The same study found that roughly 80 per cent of surveyed beekeepers had heard of biomechanical methods such as queen caging, sugar dusting and induced brood breaks, but few had adopted them, citing the constant threat of reinfestation from feral and neighbouring hives as the main barrier [9].
Breeding for Varroa-sensitive hygiene, a behavioural trait in which worker bees detect and remove mite-infested pupae, is the long-term play that Australian researchers have been pursuing for years, including through the Plan Bee national genetic improvement program. Whitehouse and colleagues identify host-resistance breeding as one of the few strategies with a permanent effect on mite populations, rather than a seasonal one [8]. The catch is generational. A hygienic breeding line takes many years to develop, and the genetic stock disrupted when 48 Plan Bee queens were removed and rehomed in 2022 is not easily recovered.
What is missing, and what the current policy debate understates, is a coordinated national plan that links hive registration, treatment compliance, feral-population monitoring and horticultural pollination forecasting. Plant Health Australia, the national coordinator of plant biosecurity response, frames invasive pests as a strategic threat to the farm-gate goal of A$100 billion by 2030, with pests estimated to cost 40 per cent of global crop production each year [10]. Varroa fits squarely into that framing. The next two pollination seasons, in almonds first and then across the rest of horticulture, will show whether the response now matches the scale of the disruption.