The robber screen prevents reinvasion of Varroa mites

Sibylle Kempf from Germany gives her thoughts about the use of robber screens when helping the bees to develop Varroa resistance. The apiary above where the hives are very close to each other is not one of hers. (If you don’t see the picture click on the headline so you arrive at the page with only this post.) The picture  shows a common way to place hives in Germany. It’s better if you can place them much further apart:


In nature, the bees would never live close to each other. To live as close as is often the case in our apiaries promotes disease and mite transmission and there will be big difficulties to find out which one are the better for making splits or queen breeding.

  My hives are spaced quite far apart compared to how many do it in Germany


Since none of us where I live have big areas for ourselves available, we have to think what would be helpful to avoid the drawbacks this create. I think a setup with a few meters distance and the entrances in different directions helps a lot.


The bees have killed a hornet that have dared to enter the hive. They have no problem getting rid and clean the hive of the dead hornet.


In addition, you can use devices to hinder robbery, obvious strong robbery, and so called silent robbery that you have hard times to discover, but can cause a lot of so called reinvasion of mites. Small entrances and a robber screen all year round have had no disadvantages to the air conditioning and traffic of my colonies even with so called closed boards (not screened bottom boards). Also I have seen that the bees have had no problems to pull out the dead, as you can see in the hornet picture.



I have put a box with brood frames (without the queen) above the queen excluder to make a finisher for the grafted queen cells. An extra entrance above the queen excluder help drones to leave the box. It also hinders silent robbing.


When making a queen cell finisher after grafting, you can use the robber screen on an extra entrance above the queen excluder for the drones which will follow the brood frames moved up there.

So you can easily put on the box on the excluder for a finisher without shaking off the bees. The bees can protect the honey easier from robbers with the robber screen on.


The robbery within an apiary is prevented with a robber screen on all the hives, even when making small nucs and splits and placing them in the apiary when there’s no flow.


I calculate that drifting is prevented by about 40% with this robber screen in place. I estimated this when comparing the lighter colored elgon bees with my grey carniolans. Not much mixing at all between the colonies, not even the drones drifted.

The robbery within the apiary is completely prevented, so it is also possible to place weak colonies, e.g. nucs and splits, very well protected.

If all beekeepers would use robber screens, it would also hinder my bees to rob hives of other beekeepers and thus hinder the spread of mites through reinvasion.

The only downside I have found is that bees could be easier taken by hornets and dragonflies. Sometimes they did not fly out, but stayed behind the screen when a hornet was hunting. But if the hornet went in, then the bees surrounded it and killed it.

I think I will put the screens with the openings sideways this coming season, to make it easier for the bees to leave return.

The Fire Brigade saved my bees


Yesterday several agricultural buildings burned down on a farm. Close to one buidling I have some beehives. The closest maybe 6-7 m (20 feet) away.

When I got the telephone call and was on my way in the car I thought it probably was the fan engine in the grain drier that started it – and it was – a worn out bearing probably. The buidling closest to the bees consisted mainly of a plankwall and a roof. The plankwall will burn relatively quickly if it’s on fire, I thought. And the honey will insulate long enough for the bees to make it, I speculated. But if the fire have caught the storage buidling with woodchips the bees are in trouble.

Brand1 The plankwall had been just on the other side of the Fireweed. In the background to the right there are remnants of grain silos.

When I arrived 1.5 hours after the fire had started the biggest building were almost burned down. The plankwall was burned down. The woodchips was saved by The Fire Brigade. The Fire Men were working saving the machine hall, and thus also another buidling behind it.

Brand2 The Fire Men working saving the machine hall.

The hives were somewhat warmer than expected but the bees looked normal. They were saved too. The lemonade in the hornet trap had dried up and the trapped hornets were very dry…The plastic in the trap had began to be deformed, by the heat that it had experienced. I just had to tighten the slit and pour some new lemonade in it.

Brand4 The deformed hornet trap, very effective by the way. The lemonade and the dead hornets had dried up. I just had to refill it and tighten the slit.

The farmer had a much worse time ahead, but a lot was though saved by the Fire Brigade.

Drone Congregation Area

I lifted off the roof from the hive and saw at the same time how the dead drone on the roof slowly began to glide off it down into the grass. During a fraction of a second I saw that the drone had the mating organ depleted. It had mated, died and fallen down on the hive roof. That is, it had mated just above the hive or not far from it. The apiary was a drone congregation area. It had to be documented. I had the camera with me lying in the car.

But I realized when the drone fell down into the grass that it was too late. I would never find the drone and put it back on roof and photograph it. And I never did.

The apiary is situated in a little hollow, not a perfect place according to some as it would keep cool air in the winter. But the sun warmes the place and it has bushes and some trees that give shade during part of the day. Close to spring flowers, water supply and good summer flow. Upwinds are said to be a part of the forming of drone congregation areas, where virgin queens mate. It seems that the apiary happens to be a drone congregation area.

By the way there were two splits that had virgins ready for mating now.