THE FOLLOWING WAS LAST UPDATED ON MARCH 18, 2012.
I noticed the bees fanning the humidity from one of the hives today and thought, “I wish I had a screened inner cover for that hive.” So I built one. (They’re also known as ventilated inner covers.) I had already built a rim or eke, constructed exactly like a ventilator rim, but only about two inches high and no holes in the sides. I simply cut an entrance at one end and stapled on some screen. It looks like this:
The bottom side looks like this:
The entrance looks like this:
I’ve already installed it below a ventilator rim on Hive #1, the hive that has the best chance of producing honey this year. I’ll let you know how it works out by the end of August.
UPDATE (Aug. 31/11): I made two more of these screened inner covers today. It’s not the greatest design, but it’s worked extremely well in combination with the ventilator rim on Hive #1. That hive is now on its way to filling a second honey super. Two improvements I might make to the design: 1) Use #8 hardware cloth instead of standard insect screen. I still haven’t found anyone in a local hardware store who’s even heard of hardware cloth. 2) Add something to the bottom of the rim so that the screen isn’t completely flat against the top bars when it’s put on. The bees need enough room to be able to crawl over the top bars but beneath the screen, if that makes sense. I used a couple layers of duct tape, but it’s not the best solution. There must be an easier way to build these things, but for now, this will have to do.
UPDATE (Mar. 18/12): Here’s another design that’s probably better than mine from Honey Bee Suite.