Apivar 2.0 and Absconding: What Beekeepers Are Reporting This Fall, and How to Keep It From Happening to You

Apivar 2.0 and Absconding: What Beekeepers Are Reporting This Fall, and How to Keep It From Happening to You

If you have been on beekeeping social media in the last week, you have seen the Apivar 2.0 thread. On September 25, Kamon Reynolds of Tennessee’s Bees posted that he had been hearing from commercial beekeepers with very poor results from the new strips, and that his own July test yard lost roughly three quarters of its colonies, most of them by absconding. Within days the post had close to two hundred comments, and the comments are the useful part, because they do not all say the same thing.

Two things up front. We sell oxalic acid vaporizers, so you know where we stand, and we have laid out the sourcing below so you can weigh it yourself. And nobody, including us, has proven what went wrong in those yards. What we can do is show you the pattern in the reports, what the label says, and how to protect your colonies while the question gets answered properly.

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What changed from Apivar to Apivar 2.0

Amitraz strips have carried commercial beekeeping for a decade, and there is nothing wrong with the idea behind the new version. Véto-pharma lowered the amitraz concentration and redesigned the strip so the active ingredient comes out faster, with the goal of a bigger mite drop in the first three weeks and less total chemical in the hive. The label facts, from the manufacturer’s own materials:

Hold on to two of those rows. The strip is designed to release faster, and the label sets no temperature limit. Both matter for what follows.

What beekeepers are reporting

Everything here comes from Kamon Reynolds’ public post and the public replies under it. We have paraphrased rather than quoted, and we have named only Kamon, since the post is his.

Kamon’s own trial, July, Tennessee. Roughly 75% of the test group lost, with adult bees leaving the hive and hanging in nearby trees, brood left behind. These were not marginal colonies: under 1.5% mites, new 2026 queens, new comb, packed double deeps. The weather was mid-90s with very high humidity. His conclusion was that until the difference between the good and bad reports is understood, he is not comfortable recommending the product, and that anyone who does use it should test a handful of colonies before treating an operation.

Reports of losses in the replies:

• A commercial beekeeper who treated more than 160 colonies through a month of 100-degree days pulled every strip and saved most of the bees.
• An Oklahoma beekeeper tested 12 hives in upper-90s heat and lost 8 within a week. The four he pulled the strips from kept their queens, but they stopped laying for about ten days before starting again.
• A club education yard lost several colonies to absconding and will not use the product on client hives unless the weather is cool.
• A Saskatchewan operation that treated 140 colonies in spring saw no absconding, but questioned whether the treatment worked: some hives were at 30+ mites per wash by fall.

Reports of no trouble:

• Northern New Jersey, nine hives, daytime highs in the mid-70s to low 80s.
• Southern Illinois through a humid spell in the 90s, at the full label dose of two strips per deep. This is the one clear hot-weather success in the thread, and it deserves weight.
• North Georgia, hives in shade.
• Hundreds of colonies including nucs, treated in spring.
• East Tennessee, single deeps, one strip per box, followed by oxalic acid vapor six weeks later.

Kamon’s own read of the replies was that many of the good results came from people who used less than the label dose or treated in cooler weather. Auburn University’s bee lab replied that it is organizing a multi-state ring test this fall, with UGA, the University of Florida, Texas A&M, Oregon State, Washington State, USDA Baton Rouge and Betterbee, to compare the original Apivar against 2.0. That is the right way to settle it. It will not report before winter.

The pattern, and why it is worth taking seriously

Line the reports up and one variable separates most of them: heat. Every loss report that gave a temperature came out of a spell in the mid-90s or hotter, usually humid, usually in large colonies at full dose. Nearly every no-trouble report came from cooler weather, shade, spring, single boxes, or a reduced dose. The Illinois exception, a full-dose treatment through a humid 90-degree stretch with no losses, is a reminder that heat alone does not explain everything, and that a proper trial is the only way to know what does.

That is consistent with how the product is built. A strip engineered to give up amitraz faster is going to give it up faster still in a packed, humid double deep at 98 degrees. Nobody has proven that is the mechanism, and a fair number of commenters pointed out that late-summer heat causes some absconding on its own. But the label says no temperature restriction, and the field is saying otherwise, and until the ring test reports, the field is the only data there is.

The most useful thing in the whole thread is the advice Kamon gave and several others repeated: do not put a first-season product into your whole operation at once. Treat a few colonies, wait a week, and look.

Why “wait for cooler weather” is really a decision about oxalic acid

The consensus fix in the thread is to hold the strips until temperatures drop. Here is what that means on the mite’s calendar rather than the thermometer’s.

As the weather cools, the queen slows down and the colony heads toward broodless. In a broodless colony every mite is riding on an adult bee with nowhere to hide, and one oxalic acid vaporization reaches all of them. Al Toufailia and colleagues measured 97% mite kill from a single winter sublimation. No six-to-ten-week strip produces that number, in any weather, because the strips are working against a brood nest that keeps sheltering mites the whole time.

So the question is not really “when is it cool enough for the strips.” It is “why put a two-month synthetic in the hive in the one season a ten-second organic treatment does the job outright.” When is my hive broodless shows how to find, or make, that window in your climate, and the month-by-month treatment schedule puts it on the calendar.

What oxalic acid brings to the fall that the strips do not

None of that makes amitraz useless. It reaches a brood-right colony in a way a single vaporization cannot, and we cover that trade-off honestly in oxalic acid vs amitraz. But in the cool season, with the brood nest shrinking, the case for a two-month strip gets thin, and this year it comes with an unanswered question attached.

If Apivar 2.0 is already in your hives

• Get a number. Do an alcohol wash now so you know where you are starting from. How to do a mite wash takes five minutes.
• Walk the yard and look for the signs people are describing. Bees clustered outside the box or in nearby trees, a sudden drop in adult population with brood still in the frames, a queen that has stopped laying. That is not a mite collapse; a mite collapse looks different.
• If you see it, pull the strips. Every beekeeper in the thread who pulled early saved most of the colony. The Oklahoma queens resumed laying within two weeks.
• If you do not see it, keep watching, weekly. Cooler days ahead work in your favor. Scrape and reposition the strips at the midpoint as the label directs.
• Plan a broodless oxalic acid treatment regardless. Two months of contact is not proof the strips did their job, and the Saskatchewan report is a reminder. One vaporization once the queen shuts down is the cleanest mite kill of the year, and several beekeepers in the thread run exactly that: whatever the summer treatment was, oxalic vapor cleans up in late fall.
• Wash again after. The only treatment you can trust is the one you measured.

If you have not treated yet

If your colonies are still raising brood and your count is over threshold, you need something now, and the choice is between a treatment that reaches capped brood and a series of vaporizations spaced a week apart to catch mites as they emerge. Formic Pro vs oxalic acid lays out the brood-penetration trade, and the full treatment guide compares every option side by side.

If your count is under threshold, the highest-value move is to do nothing chemical until the colony is broodless, then vaporize once. That is the treatment your winter bees are counting on, and why colonies die in January explains what happens when it is skipped.

Related reading

• Oxalic acid vs amitraz (Apivar): resistance, residue and what each one costs
• When is my hive broodless? How to find (or make) the treatment window
• Does oxalic acid vaporization actually work? What the studies show
• Why did my bees abscond? How to tell if they left or if mites killed them
• Varroa mite life cycle: why timing beats dosage

Sources

• Kamon Reynolds, public post and replies, Facebook, 25 September 2026
• Véto-pharma, Apivar 2.0 product page and “Apivar 2.0: quicker action against varroa mites, with less amitraz”
• Atlantic Tech Transfer Team for Apiculture, “What beekeepers should know about Apivar 2.0”, December 2025, and “Review of new varroa management tools”, September 2026
• Rinkevich, F.D., “Detection of amitraz resistance and reduced treatment efficacy in the Varroa mite, Varroa destructor, within commercial beekeeping operations”, PLOS ONE 15(1): e0227264, 2020
• Al Toufailia, H., Scandian, L. & Ratnieks, F.L.W., “Towards integrated control of varroa: 2) comparing application methods and doses of oxalic acid”, Journal of Apicultural Research 54(2):108–120, 2015
• EZ-OX Tablets label, EPA Reg. No. 101743-2, US EPA, 2026

Happy Beekeeping from the Lorob Bees Team

General beekeeping information, not a substitute for the product label. Always read and follow the label of any product you use in a hive. Reports quoted from public social media are the experiences of the beekeepers who posted them, not controlled trials.