Why the Hell Did I Treat for Varroa?
If you practice some sort of IPM (integrated pest management, for the uninitiated), and treat for Varroa Destructor, you’ve heard just how important it is to follow, exactly, the directions on the labels of the various mite treatments. After all, any variation from the approved treatment method is a violation of Federal law (I’ve never heard of anyone being arrested by the mite treatment police, however).
You may have had bee store personnel, fellow bee club members, mentors, etc… stand on their soapboxes & tell you that you must follow the directions on the package to the letter – I’m looking at you, oxalic & formic acids.
But sometimes, those directions steer you wrong, which breeds distrust in those directions. And maybe that’s a good thing.
When Opportunity Knocks, Hide
Last August, here in Central North Carolina, we had a cold snap (relatively). We were in the dog days of summer, and temperatures were forecast to be between 79-84 (highs) for three days in a row.
I was due for a varroa treatment, so I jumped at the chance to have temperatures within manufacturer recommended levels. (Post image of recommended range)
August is nothing but dearth here (no nectar), so I felt safe in slapping a few formic acid strips on my hives for a few days. As a quick aside, formic acid kills varroa under capped cells, oxalic acid does not. Oxalic acid is great for pre and post brood cycle times, like late fall.
If I’m honest, I was a little nervous about using oxalic acid. Formic strips are just easy, and I’d never used oxalic acid. I’ve since used oxalic acid, with no ill effects (dribble method, I haven’t invested in a vaporizer).
In retrospect, I was going to have trouble anyway. The temperature likely would have risen outside of the recommended ranges before the treatment period was over. That’s my fault. But I never got the chance to make that mistake.
Within minutes of applying the formic strips, bees began pouring out of all three of my hives. Uh oh. Maybe this should have been a warning sign, but I figured they would hang out on the outside of the hive for a bit, then make their way back in at nightfall. Even though I never experienced a similar reaction to the prior application of formic acid strips, I trusted in the process. In retrospect, I should have pulled the strips off immediately.
But the bees did not return to the hives. Come nightfall, they just sat on the outside of the hive. And in the morning, they were still there.
Over the next two days, one of three hives returned home. So I figured the others would, too.
One hive absconded. Dammit. Still, I had one hive rehomed and one strong hive hanging out on the outside of the boxes.
The next day was a Saturday, and the morning found no bees on the front of any hives. I had someone coming over that wanted to inspect the hives with me. He grew up with bees, and hadn’t had them in 20+ years, but was eager to return. So we opened my boxes. The first hive we opened, the one that was covered with bees the night before, was empty.
Only not empty. It had residents, just not bees. Larvae. Small hive beetle larvae. Without a strong hive to corral the SHBs into corners, and other hard to reach places, the SHBs were able to take over. And they did, quickly. The frames were slimed. The bees, disgusted with the state of their home, sought their fortunes elsewhere. That’s two hives absconded since the application of the formic acid strips.
I was pissed and embarrassed. Who the f*** loses hives to small hive beetles? They’re a pest, but relatively easy to manage. Unless, of course, you put a chemical in the hives, that under the improper conditions, vaporizes & creates an odor so noxious it pushes the bees to abandon their hard-fought honey & pollen stores. So strong, that they abandoned the brood.
I’ve checked several times, and the recorded temperatures were within the temp range. So was I wrong? I could have done more for SHB management (and since have – Swiffer pads, beetle blaster traps, etc…), but I don’t think that would have made a difference, as the bees just weren’t there to chase the beetles into the traps.
So be careful with your treatment procedures. Stay away from the limits of the ranges – subtract a few degrees. It’s just not worth the loss. Maybe I’m the only idiot that has had something like this happen, but maybe not.
It’s anecdotal evidence at best, but I’ve spoken with several people from the North Carolina Beekeepers Association to let them know. If you’ve had a problem like this, reach out to the manufacturers or retailers varroa treatments. If I’m not alone in this, and enough of us have experienced a problem like this, maybe they’ll update their recommended ranges.
As beekeepers, we’re facing enough problems. We need to be able to rely on the best information out there in order to keep our hives alive and healthy.
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