Amitraz is losing its efficacy, or maybe I should just say it’s lost its efficacy (it still works in Canada). At the state meeting, it was reported that 10 percent of Varroa are now resistant to Amitaz here in Oregon. Harry Vanderpool, in his last presidential message, shared how talented beekeepers are struggling to keep mites under control. He thinks an industry-wide collapse is possible in a few years. Russell Heitkam, a California commercial beekeeper, ventured a guess that we might see a 50 percent loss this year (2018). It strikes me that things are significantly askew now. The “Varroa Paradox” (just coined that) which Michael Burgett referred to—how Varroa has actually been a boon for commercial beekeeping by dramatically increasing pollination demand —does not seem to hold true anymore for some beekeepers.
I don’t see the future as quite so gloomy. I suspect many of us have already made significant changes in how we treat for Varroa. I’m even optimistic that some of our main tools—for example, oxalic acid—will remain viable long term. I know what you’re thinking: Yeah, right! It is suggested that Varroa would have to fundamentally change to become resistant to oxalic acid, like grow thick foot pads, at which point it would no longer be the virulent pest that it is today. Bacteria have not yet evolved resistance to soap and bleach. They’ve had thousands of years. For bacteria to develop resistance to soap, they would need to develop a cell membrane of totally new material resistant to soap – something other than proteins and lipids. Just maybe Varroa will need to overcome oxalic acid similar to how bacteria need to overcome soap. Randy Oliver shared a study that supports this idea: Varroa populations continuously exposed to oxalic acid over time became even more susceptible to it than the oxalic-naïve populations.
Baseline of Beekeeping Today
I have always told people that if not for the almonds, there’d be half the number of hives in the United States. Pollination rates may approach $230/hive for almonds this spring. Commercial beekeepers are incentivized to meet this demand but clearly at a cost. In many areas, carrying capacities are being exceeded, and mites and diseases are being spread between apiaries. Mite loads may vary significantly between locations.
Varroa mites are more lethal. The recommended threshold for treatment is now 1 percent or less. Multiple treatments are required throughout the year, and the brood-rearing season in lengthening.
It was reported that for some beekeepers mite counts spiked in previously healthy, mite-free hives after August treatments. Significant losses have been attributed to this phenomenon. Data suggest mite loads are increasing dramatically in the fall in a short period of time, and that our current mite curves are flawed.
Queen breeders cannot meet demand, period.
Lastly, small hive beetles are becoming more ubiquitous—yes, here in Oregon.
Do you have bees that can survive without treating for Varroa? I don’t. I’ve gotten by the last two years using formic and oxalic acid. I’m not knowledgeable about how to use thymol/Apiguard. Someone else can cover that. I will share my insights on how I use formic and oxalic acid. Mind you, I am no expert—just a sideline beekeeper who runs around 100 hives (104 healthy hives right now).
Formic acid: It kills Varroa under cap brood. I use the MAQS. I’m cautious when I use formic—and definitely more so later in the season. I typically place two pads on top of the brood nest. Last September for maybe 5 percent of my hives I followed the directions and placed two pads between the brood boxes—and I think every one of these hives died. Why? It wasn’t too hot. They may have already been too compromised from Varroa, then getting knocked down even more predisposed them to robbing and yellowjackets. The other hives did just fine.
I think the bees can tolerate formic acid better in the middle of the summer during the honey flow. I’d experiment with different dosages at that time—maybe just one pad between brood boxes. I’d remove the queen excluders and allow the queen to escape upstairs if she wants. She may be honey bound upstairs, anyway.
Oxalic Acid: I use oxalic acid by far the most. Formerly I used the dribble method, but now I only vaporize it or use Randy Oliver’s glycerin/oxalic acid shop towels.
Vaporizing: It is pretty darn simple, and fast. I use the ProVap 110 Vaporizer (aka crack pipe as Harry Vanderpool refers to it). I use an extension cord along with a small Honda generator. Some have questioned the delivery system of the ProVap, including Randy Oliver. I know Randy was given one, and I think he’s using it. He hasn’t said anything bad about it except that it is dangerous. FOR SAFETY REASONS, if you use the ProVap 110 Vaporizer, wear both a gas mask and eye protection. If the pip outlet is blocked, pressure will instantly build and forcibly pop the white cap off sending molten oxalic flying in the air. I’ve seen it happen.
Glycerin/Oxalic Shop Towels: Recently in Bee Culture Jennifer Berry resoundingly pooh-poohed Randy Oliver’s glyerin/oxalic shop towels. I also remember when I was strongly critical of Randy’s suggestion of putting a certain amount of Apiguard (thymol) between the brood boxes. It worked for Randy; for me, it was devastating to my hives. That was a lesson. I will not give up on the glycerin/oxalic shop towels. It’s never been hard on my bees. I’ve seen it work, and NOT work. This is my opinion (Randy’s the expert; he collects empirical data, bless his soul for the service he provides us!). The shop towels work when the bees make attempts to remove them, thereby spreading and disseminating the oxalic acid on the bees and within the hive. If they ignore the towels, have a Plan B. Some more-subtle observations: the bees are more likely to work the towels midsummer when they’re expanding and building; in autumn, a higher percentage just propolize over or, worse, ignore them.
When to Treat?
I treat during windows when the mites are phoretic at historic treatment times (first of August), and sometimes randomly based on mite samples or even visual cues that mites have become a problem.
I treated in early December (vaporized oxalic), May (vaporized oxalic—all hives, including mating nucs), July (a few hives with glyerin/oxalic shop towels), August (glyerin/oxalic shop towels), September (formic acid), and October (right before the state meeting, vaporized oxalic again). This coming year, I’m either going to use glyerin/oxalic shop towels or formic acid most likely in June during the honey flow. And I will definitely keep an eye out for that mite push in late summer/fall.
Consider Raising Your Own Queens
I started the process in late April last year with mating flights in May. Yes, Alan Ehry, I finally raised my own queens! Alan’s rolling in his grave. Do you remember the Life cereal commercial, “Mikey Likes It!”? The premise was, if Mikey liked it, then everyone would like it. A corollary to this is if I (Todd) can raise my own queens, then everybody else can raise their own queens. I literally just watched a few YouTube videos, purchased JZ-BZ queen cups, a Chinese grafting tool, and a specialized frame to hold the queen cell bars, and off I went. Making cell builders was easy; ditto, cell finishers. The lion share of work (95 percent) was making the nucs for the queen cells, and this is exactly the same if you purchase queens. There are some definite positives to raising your own queens:
1. I felt like I was printing money. This was a unique feeling that you may want to experience. Queens cost about $30 apiece, so it is financially rewarding.
2. You get to choose your breeder queens. I’m propagating from my very best hives.
3. All the mites will become phoretic in the mating nucs allowing for another highly effective oxalic treatment. (Incidentally, Varroa feed on the fat within the bee, not on the blood.)
4. You get to raise queens for when you want them. Sometimes it is hard to get queens, especially early in the season.
Small Hive Beetle
I see them every year now—just a few. They’ve yet to be a problem, but the potential is definitely there. I keep an eye out for them at locations where they could become a problem. Keep division board feeders clean; make sure the bees clean them out and that there is not a residue of heavy syrup at the bottom. Look at frames, especially those with bee bread, especially frames in mating nucs, weak hives, and in dead outs. Make sure there’s no signof small hive beetle larvae burrowing through the frame. Burrowing larvae leave little telltale signs of where they’ve been (analogous to looking for razor clam holes on the beach). I don’t burn the frames. I put them in the freezer. When I take honey off, I extract immediately. It works out best this way anyway. I store supers dry.
Tips for January and February
I can’t think of a lot to do at this time of year except find those populous light hives and give them emergency feed. One of my best hives last year was a bunch of Italian girls that I saved from the absolute brink of starvation.