Having kept bees in the 60’s and returning to beekeeping a few years back was an eye opening experience to say the least. A little insect, by the name of the varroa mite was never around in the 60’s . The worst that could happen to a hive back then was European foul brood. Of course the treatment for that was fire and then start over.
I read and watched the video’s when I got back into the game and figured “how bad could the varroa be ?”. Went to the screened bottom boards, installed 4.9mm (small cell) foundation into new equipment and of course started with package bees. A fresh start that I figured for the first year would easily carry me through on my four hives.
Yes, I knew that I would have to do something about the varroa later in this venture, but not the first year. The four colonies’s flourished and produced excess honey the first year. The queens were doing a phenomenal job.
Went into fall with, what I had considered a few mites on the tray below the screen bottom board. Normal I thought. Isn’t that what I’ve been reading about ? No problem. I had left plenty of honey for the four huge colonies. I made sure that the hives had ventilation, wind brake and everything that they would need to make it through the winter.
Winter came and on occasion I would listen to make sure that I could hear the hum of the bees keeping the hives heated. By Christmas, only two hives still hummed. By March, only one hive showed any life and by spring the few remaining bees in hive four, never had a chance. I concluded, that my first year back into beekeeping, I had forgotten everything that I had ever known about beekeeping.
More packages were ordered, more videos watched, and more reading about winter loss. After a careful postmortem of the hives, poking through the mounds of dead bees on the bottom board. Honey right next to many of the dead bees and some uncapped brood, I concluded that the varroa mite got the best of me and my bees. The population going into winter was strong, but as the season continued the mite got the upper hand. As the population died off, there were just not enough bees to maintain the hive and the obvious happened.
So now what ?
I have a profound respect for that little insect we call the varroa mite. If you have bees, whether a package, or a swarm catch. you have mites. Not many at first, but as the season progresses they will increase in numbers, the same as your colony does. But when fall comes around and the honey bee numbers decrease, their numbers will not. Left untreated, in some manner, you WILL lose that hive.
I have no doubt that there are those that are keeping bees that are not using any treatments other than small cell foundation, and screened bottom boards are having some success. I would be willing to bet that they are also not buying any packages and are probably in an isolated area that have no other apiaries that they do not manage. I am not one of them.
For the rest of us, we do have some options. It was just reported that this past year, beekeepers lost 44% of their colonies in the United States. Varroa mite infestation was one of the main reasons reported for the loss.
I am not an advocate for commercial insecticides used in the hive. Trying to kill an insect on an insect sounds pretty complicated to me. Remember also that you are selling a pure product to the consumer and when they ask if you use any chemicals in the hive, you can tell them no, truthfully.
We do have some options that are found naturally in honey and nature. The only one that I have used and have experience with, is oxalic acid. There are two methods for treating. The dribble method and the vaporizer.
I am not going to go into detail about rates or treatments. There is a great deal of information on the internet on both treatments. This is not the only treatments available, so I urge you to do some studying on the subject and ask beekeepers what they use and how.
Fellow beekeepers, you will have a chance to see a vaporizer in action at our upcoming field day, June 4th at Fred Ransome's "Flying Squirrel Apiary ”.
Details in Our Bee Blog.
This article provides a little feedback on the previous article asking for clubmember experience with small cell foundation.
ReplyDeleteI have no experience with oxalic acid, but my understanding from Dr. Michael Goblirsch (UMN, Spivak Lab) is that it is an effective treatment but can only be used in the 30 - 50F temperature range, and should only be used if there's very little to no brood present. Oxalic acid will not penetrate cell caps so any mites under the caps will do fine.
ReplyDeleteMy personal treatment has been formic acid (e.g., Mite Away Quick Strips (MAQS)) which is considered organic as it is naturally found in honey and can be used with honey supers on (although I haven't). MAQS can only be used in a temperature range of 50 - 95F and a full dose will penetrate cell caps killing the mites underneath.
According to Dr. Goblirsch, both treatments cause "mechanical" damage to the mites and so mites will not adapt to it. He very much favored oxalic acid in the early spring before the queen goes into high gear, and in late fall when she slows down. However, a recent article I read said that we need to knock out mites before the winter bees are started which is late July/early August.
These two treatments complement each other well for times of year, and I intend to use the oxalic acid drip method in late fall for extra insurance.