Bees: More about Mites

My own observations prove another beekeeper’s theory true.

I started my beekeeping hobby in June 2013 and have been blogging about it periodically. If you’re interested in reading the other posts in this series, follow the Adventures in Beekeeping tag. Keep in mind that the most recent posts always appear first on this blog.

As I mentioned in a previous post, I’m concerned about varroa mites in my beehives. Mites can weaken a colony to the point that winter survival is impossible. Since I’d like all my hives to survive the winter, I’m starting a war on mites now, before it’s too late.

My Setup, as it Relates to Mites

There’s a few points I want to make here without spending a lot of time on a long narrative.

  • My three hives come from two sources:

    • My original hive was a nuc I purchased from a beekeeper in Peshastin. That hive grew and thrived very quickly, producing 2-1/2 gallons of honey in about a month. When a hive inspection showed signs of swarm cells, I split it off to form my third hive.
    • My second hive was a swarm capture. The swarm came from a colony living in the wall of a friend’s shop building. These are as close to “wild bees” as you can get.
  • My hives aren’t all set up exactly the same way. As I experiment with different hive components, I use them on different hives. For example, my first and second hives have standard wood bottoms while my third hive has a bottom with a varroa trap screen drawer. When setting up this third hive, I placed a sticky board in the drawer and left it there for about a month (which is really too long.)
  • My first and second hive have drone frames installed. As I discovered earlier this month, the drone frames work — once they’re adopted by the bees — and my first hive was confirmed to have mites.

Mite Count

On Wednesday, after a normal hive inspection, I placed sticky boards (with screens) in my first and second hives. Remember, I’d already learned that my first hive had mites; the idea behind the sticky board was to see how bad the mite problem was in each hive. Because I’d left the sticky board in the third hive so long, I couldn’t really gauge the mite problem. So I got serious for this test and left the boards in for just two days. If I had a third board, I would have tested that third hive again, too.

Mites on a Sticky Board
I’d say this hive has a mite problem, no?

When I pulled them out yesterday morning, I was surprised to find that the sticky board from Hive #1 was full of mites. Here’s a magnified image of just one square inch of the board. The dark ovals are dead mites — you can even see the legs on a few of them. The light ovals are also mites, but I don’t know if they’re some sort of shedded skin or exoskeleton or the actual mite itself after being dead for a day. The other dots on the image are mostly litter from the hive as well as some propolis that the bees laid down between the holes on the screen. Keep in mind that this sticky board has 176 square inches and although not all of them are as full of mites as this one, some are a bit worse.

All this was gathered in less than 48 hours.

But what was even more surprising to me — at first, anyway — was that the sticky board for Hive #2 had very few mites on it. In fact, because I pulled it out first, I thought that I’d pulled it out too soon. It wasn’t until I pulled out the other sticky board that I realized that the boards had done their job; I just had far more mites in one hive than the other.

Why the Difference?

Last night, I was at a BBQ gathering of helicopter pilots and mechanics who are based in the area for fire season. One crew — pilot, mechanic, and fuel truck driver — are based in a really nice house in a farm just down the road from where I’m currently living. They had a fire going in the fire pit and grilled up some steaks and brats and corn. It was a really nice night out.

I got to talking to one of the pilots, a guy who flies the Cessna Skymaster “push-pull” used for observation and direction to fire crews. He lives in the Snohomish area of Washington and keeps bees at home. We got to talking about mites and he asked me where I’d gotten my bees. When I explained their source, he told me that commercial bees always had mites.

I thought about what he said. It completely jived with what I had observed. The hive from the nuc had a bad mite problem. The hive from the swarm had very few mites at all.

He said that because so many hives were moved around for pollination, the mite problem spreads. He keeps mites out of his hives by keeping them away from commercially available bees.

Certainly something to think about.

Three Means of Attacking Mites

Because I’m serious about eliminating — or at least greatly reducing — the mite population in my hives, I’m currently using a two-prong attack:

  • The drone frames, as I discussed in another post, can help concentrate most of the mite reproduction on one frame, where they can be easily removed. Unfortunately, the queen is far less likely to lay drone eggs as the summer season comes to a close. In addition, only one hive (so far) has adopted the use of the drone frame.
  • I’ve purchased a miticide and dosed each of my hives with it. Although it can’t be used when the bees are producing honey for human consumption, using it now, before winter, should help reduce the number of mites and make a stronger hive.

The third method, which I hope to be able to institute soon, is to have sticky boards beneath screens on the bottom board of each of my hives. While it would be great to do this via a varroa trap with drawer for each hive, the $27 price tag makes that a bit more than I want to spend. So I’ll likely cook up my own solution using some “hardware fabric” I already have on hand to make the screen. I’ll talk to a beekeeper friend to see what we can rig up.

In this area, bee colonies have a 50% overwinter survival rate. I have three hives. I want to have all three colonies survive the winter. That’s going to take some work — and I’m willing to do it.

What do you think?