One of the more sobering realities of varroa management is that what happens beyond our own apiary fence can still arrive at the entrance of our hives.
Across parts of the Northern Rivers, beekeepers are seeing a pattern that may become increasingly familiar: some apiaries suffer sudden colony losses, while others only a relatively short distance away remain stable.
This uneven pressure can be confusing, especially when hives have received similar treatments.
In some areas, the first major collapse of wild or unmanaged colonies may already have occurred. In others, it may still be unfolding. Either way, the risk does not end when those colonies die.
Dead-outs, abandoned hives and neglected equipment can continue creating pressure for surrounding beekeepers long after the colony itself has failed. As the work and cost of managing bees increases, there is also a real risk that some beekeepers will simply walk away from hives they can no longer manage.
Those unattended hives can become a serious biosecurity problem.
A local example is worth considering.
Brian Window has an apiary just west of Coraki where he has lost around half his hives, mostly through absconding. In many cases the colonies left behind only a small number of bees and apparently healthy capped brood. Small Hive Beetle then moved in quickly.
John Bull has seen similar losses at Tatham, a few kilometres further west.
By contrast, Brian’s small apiary at home in Lismore and John’s small apiary near Casino have so far experienced no losses, despite similar management and treatment approaches.
That difference matters.
It suggests that some sites are currently under much heavier reinvasion pressure than others. As unmanaged colonies collapse nearby, surviving managed colonies may suddenly receive an increased load of incoming mites. A hive that looked strong only weeks earlier can shift into trouble surprisingly quickly.
Small Hive Beetle can also increase sharply during this process.
A strong colony normally controls beetles well. Bees patrol comb surfaces, harass beetles into corners and confine them into cracks and crevices where they can be trapped.
But when colonies collapse, beetles suddenly lose both food source and shelter. They are highly mobile opportunists and can move quickly in search of another weakened colony.
As managed colonies move into the colder months, forage becomes less abundant and harder to find. Dead or collapsing hives can then become magnets for hungry bees looking for any available stores.
This creates another serious risk.
When robbing bees enter dead-out colonies, they may come into contact with contaminated comb, old brood material, mite-infested bees, Small Hive Beetle activity and disease organisms. As they return home, they can carry more than just honey.
We are already beginning to hear increased concern about American foulbrood and other disease issues appearing in the wake of colony losses.
This is why dead hives should not be left sitting open in the field. Any dead-out colony should be closed up promptly, assessed carefully, and dealt with in line with current biosecurity requirements. Suspect brood should never be ignored, and anything showing signs of AFB must be reported and managed properly.
This means that as wild, unmanaged or neglected hives die across a district, surviving managed hives may face several pressures at once: rising mite loads, increasing beetle pressure, robbing pressure and greater disease risk.
A few numbers are worth remembering.
In a hive without further incoming mites, varroa numbers can roughly double every 30 days. Colonies may begin to fail, collapse or abscond once mite levels reach around 3–5%, which is approximately 9 to 15 mites in a half-cup alcohol wash.
But if mites are continually arriving from outside, those numbers can climb much faster than expected.
This is why regular monitoring matters so much.
Do not assume a colony is safe because it looked strong last month. Do not assume your treatment worked because the bees appeared settled for a few weeks. And do not assume that a nearby beekeeper’s experience will exactly match your own.
For now, practical steps remain our best defence:
- Monitor regularly with alcohol washes.
- Keep written records of mite counts.
- Reduce excess hive space where colonies are weakening.
- Watch closely for Small Hive Beetle pressure.
- Use beetle traps where needed.
- Keep apiary sites as dry and tidy as practical.
- Close up dead-out colonies promptly.
- Check suspect brood carefully.
- Follow current biosecurity requirements.
- Act early when colony strength begins to decline.
- Ask for advice before a problem becomes a crisis.
The difficult truth is that we are all still learning what varroa looks like under Northern Rivers conditions.
Some sites will be hit earlier than others. Some colonies will cope better than expected. Some treatments will appear to work well in one apiary and less well in another.
That does not mean we are helpless.
It means observation, timing and local experience matter more than ever.
The death of wild hives across the landscape may become one of the hidden drivers of sudden pressure on managed colonies. But abandoned and unattended dead-outs may become just as serious if they are left in the field.
The more closely we watch, record, clean up and share what we are seeing, the better chance we have of keeping our bees alive through the seasons ahead.