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The varroa incursion in Australia 4 July 2022


I’ve been speaking on a daily basis with one of the two beekeepers whose operations are infested, as well as others in the industry.
So far, over 1000 of their colonies have been euthanized, with many more planned to be burned.  As you can imagine, this is very emotional for those beekeepers, who have also been prevented from selling their massive inventories of honey on hand.
The Department of Primary Industries appears to be doing a good job of “contact tracing”(epidemiological links) and so far, all detections have been linked to these two operations.
The key issue is to define the perimeter of how far mites have drifted from those infested colonies.  My own tracking of marked bees indicates that there is considerable drift of bees from hive to hive to at least a half mile, and some to a mile.  Not to mention that a bee carrying a mite can forage for several miles away from its hive, and perhaps bump into another uninfested bee on a flower.
The obvious questions are whether mites have gotten outside of the containment zone, or established in the feral population.  If they are still limited to a small zone, there’s a feasible chance of eradication.  The concern is that it is currently winter in Australia, and some of the infested hives had high enough mite counts that it’s obvious that they’ve had varroa since at least early last summer.  This would have allowed time for considerable drift, perhaps into the hobby sector in Newcastle.
Those of us who have lived through the invasions of tracheal and varroa mites understand the futility of eradication if a mite is already well-established.  The offspring of even a single female mite can relatively quickly spread throughout a continent, especially if aided by inadvertent human transportation.
For better detection screening, the DPI just received a large shipment of stickyboards from the U.S. (which I’ve made clear are more efficacious at detection than are alcohol washes).  They are also working on getting registered colony treatments into the country.  I hung out the past few days with one supplier in North America, whose phone was ringing off the hook for requests by Australian beekeeping supply houses.
When I was asked several years ago by the Department for recommendations for their incursion plans, I made the point that if they were not willing to take strong actions — including using fipronil bait stations to kill feral colonies — that their chances of eradication would be zero.
Although I have only had indirect communication with the DPI during this incursion, I am encouraged that they are indeed preparing to perform such baiting.
The commercial beekeepers in the country are well aware that the possibility of complete eradication are slim, but it’s clear that the agency, based upon lack of detections outside the containment zone, feels that they still have a fighting chance.
Since beekeepers will soon need to start moving colonies to pollinate the almond orchards, restrictions on movement will need to be put into place, to prevent the dispersion of varroa throughout the country.  We all know that it only takes a single beekeeper to screw it up for an entire continent, so let’s cross our fingers that none do!
Aussie beekeepers have enjoyed having their honey and beeswax being miticide free.  Suggestions have been made for treating all hives going to almond pollination with Apivar strips.  There is of course pushback, since beekeepers don’t want residues in their hive products.
A big question is whether the strain of mites in the incursion are resistant to any miticides, so tests are being performed.  If the introduced mites are “amitraz-naive” this might be a worthwhile consideration, since such treatment in my own amitraz-free operation can actually completely eliminate every mite from a colony.
If there are any Aussie beekeepers reading this, here are some suggestions:
  • Keep a cool head.   The DPI appears to be well informed, and doing a good job.  I commend them for trying to act with transparency, and keeping the public informed.  Beekeepers can help them by cooperating fully, especially since since there will be agents unfamiliar with bees.
  • Since most Aussie beekeepers are completely unfamiliar with mites, they should view photos of mites in alcohol washes or on stickyboards, to train their eyes to recognize them.  They are difficult for the untrained eye to spot, and you don’t want to miss a single one!
  • Alcohol washes or sugar shakes of 300 bees can easily miss a low-level infestation.  An “accelerated” stickyboard count, using formic acid, rapid-release amitraz, or even whole-colony sugar dusting, will have fewer false negatives.
  • Although the chance of eradication of this incursion are slim, it is still possible, and well worth making the effort.
  • Beekeepers who are required to have their colonies euthanized will be compensated, and should consider the sacrifice to be a heroic effort to save their industry.  Australia will inevitably get infested by varroa, but the longer they can avoid it, the better for the beekeepers.  Let’s all root for success in this containment and eradication of this incursion!
Category: Mite Monitoring Methods