A controversy over screened inner covers
I hear lots of controversy over screened inner covers. Some people (like me) think they are the best thing since sliced bread, while others think they are a grotesque perversion that will breed mites and freeze bees. The truth probably lies somewhere in the middle. Screened inner covers are simply a management tool that can be used at the beekeeper’s discretion. No one is saying you must use them—they are simply an option.
As I’ve said so many times in the past, there is no one-size-fits-all prescription for beekeeping. Every colony is different, as is the local climate, and the individual beekeeper. Even in your own apiary, two side-by-side colonies probably have separate issues that could benefit from different management strategies. I have little patience for those who use the words “always” and “never” when discussing honey bees.
That said, I will begin by saying always analyze your individual situation and never listen to beekeeping dogma. So there!
Man-made systems are not natural systems
People who keep bees in man-made hives often write and say, “Do nothing that doesn’t happen in nature!” Lo! The irony. Once you decide to keep bees in a man-made structure you have already departed from what happens in nature. You can try to emulate natural systems, but you need to remember that the characteristics of a man-made hive are very different from, say, a tree cavity. You can’t put bees in a man-made structure and think all other factors will remain constant.
Recently, a reader mentioned that he keeps bees in top-bar hives, he never uses screened covers, and his bees are thriving. When I began thinking about it, I realized I use screened inner covers on all my Langstroths, but not my top-bar hive. But guess what? All my colonies are thriving, too. So what does it all mean? Not much, except that a screened inner cover is a choice. It’s not the be-all and end-all of beekeeping.
I’ve never actually seen a top-bar hive or a long hive with a screened inner cover. There may be several reasons for this, including the configuration of those hives: the shape could make an inner cover awkward.
But beyond that, one layer of frames spread along the length of a long hive can probably shed heat and moisture easier than a vertical stack of frames above frames. On the other hand, a taller stack has more of a chimney effect that can draw air through the hive and out the top. The variables are endless.
Bees in trees
Bees in trees are a different subject. Those bees are better insulated and the material inside a tree cavity is more efficient at absorbing moisture—much more so than a piece of milled lumber no matter how it’s configured.
Even more to the point, tree colonies tend to be smaller and swarm more often. The size of a colony—the number of respiring bee bodies—is directly proportional to how much heat and moisture are produced. You can’t expect a colony of 50,000 bees in a man-made hive to have the same problems as a colony of 20,000 bees in a tree.
Needs vary with your location
My original reason for using screened inner covers derived from my climate. I live in western Washington or, as I call it, “the mold and mildew capital of the New World.” For those not familiar, you can visualize it like this: rain for nine months followed by three months of drought. Repeat once every year. I do whatever it takes to keep excess moisture out of my hives, and that includes screened inner covers and winter moisture quilts.
Not only did my overwintering success increase with these measures, so did my honey production. I often overwinter one hundred percent of my colonies, and that works for me.
Options and rules are different
What works for you will depend on your bees, your climate, and your management style. It was never the purpose of this website to tell you how to keep bees, but only to suggest options, or as I call them “try-its.” You have a problem and your bees are not thriving? The best I can do is offer some options and tell you why they may (or may not) work. To me, the why is the important part. There needs to be a logical reason for doing or not doing—a rumor or wive’s tale won’t cut it.
But an open mind is a valuable asset. Another reader this week, Stosh Kowalski, was searching for a way to vent the top of his hive. At the time he wrote he was propping the lid open during the day and closing it at night. Apparently, he hadn’t heard of a screened inner cover, but when I suggested it, he jumped on the idea. Except, within moments, he completely redesigned it. At first I thought, “Why the heck does he want to feed through it?” But then I realized he had his reasons and, within a few hours, he produced a screened inner cover that met all his needs.
A screened inner cover with feeding port
Here is a photo of the new inner cover by Stosh Kowalski. He writes:
Attached is the inner cover design I threw together last night. The platform the feeder rests on is oak (so it won’t flex downward and decrease the bee space); the rest is just pine. The bees seem to be very happy with it (or at least not unhappy with it). A top box goes on over this to enclose the feeder, and then the roof.
The bacon-looking thing you can see under the screen is a brace I had under the solid inner cover to keep it from sagging under the weight of the feeder. The bees have glued it down pretty well, so I just left it until the next hive inspection to deal with.
So what does the new inner cover mean to me? It means I know of another option, a variation on the screened inner cover that I hadn’t considered before. Will I use it? Probably not, but that’s not the point. The point is we can learn so much more more by accepting—or at least examining—new ideas. Immediate rejection, or rejection without evaluation, just limits your choices.
Honey Bee Suite