Robbing screens didn't seem to work?

[Javin]

So after my first bout with the robbing, I decided to build some robbing screens for my nucs to give them a shot.  At night, I removed the sheets from my nucs and placed the robbing screens on, taping them into place with duct tape.

The next morning, I went out to check the bees, and sure enough I was able to catch the occasional bee coming out of the top of the robbing screen and returning to the main hive.  I quickly checked the nuc and saw that it was still full of what I assume to be the "home" bees but even inside of the hive there was the occasional tussle where bees were biting the legs and wings of other bees in there.  Fortunately the robbers had only had a few hours to work them over, and they seemed like they'd make it if I could stop the robbing.

I threw the sheets back over both nucs since that seemed to be the only thing that worked, and since both nucs have fairly new queens, I don't want to mess with them any more than necessary. 

So my question is, why didn't the robbing screens work?  My currently prevailing theory is that the mesh I used to make them was too "tight."  I'd made the screens with some screening I had laying around, which is the kind you screen in a deck with, or make window/door screens.  (I don't know enough to tell ya how many squares per inch they are.)  When I went back to look at the robbing screens online, they're pretty much exclusively made with a mesh that's many times larger than what I used.  I assume the mesh, being so tight, wouldn't have allowed the "scent" of the hive to draw the robbers to the wrong entrance?

Any ideas how to stop a hive that loves to rob?  I'd prefer not to have to requeen since we're in a dearth, so that's probably a major factor, and the queen in the primary hive is an excellent layer with some super docile offspring.

[BlueBee]

I think robbing screens are the bee keepers version of the 100 mpg carburetor.  Something that some people claims works wonders, but nobody else can duplicate.

[AllenF]

Are you feeding the bees?   That would cause the robbing.  Block the entrances down as much as possible.  Also are the hives queen rite also? 

[iddee]

My 100 MPH carb has 1/8 in. air screen, and it works wonders. Use the same product and you will get the same result.

http://www.beekeepingforums.com/threads/5223-Robber-screen-moving-screen?highlight=robber+screen

[specialkayme]

I've used the same design as Iddee, only it won't work unless I restrict the entrance on the top of the robbing screen by one bee width. Otherwise, they just rob anyway.

[Nature Coast Beek]

From what I understand, the hive is still going to need some guard bees and enough of a population to defend itself even with robbing screen in place. It could be that by the time a beekeeper realizes what is going on, the guards have already been overwhelmed and the inner population is already on it's heels. Like most everything in life, time at which intervention takes place is probably the deciding factor.

[Javin]

Well, they're currently sitting with sheets on the nucs, which seems to work.  I just don't know how long leaving the sheets on is too long.  I'm not feeding any of them, though I understand that you could feed the robbers to reduce their desire to rob, but I'm specifically trying to see how well the bees manage if they're *never* given any sugar water.  (I realize that I'll probably lose all three hives over the winter.  Risk I'm willing to take for the sake of the experiment). 

The hives are now queenright, but they weren't when the robbing first took place.  They had three frames of brood in each nuc, so I'm hoping that given enough time, those frames will hatch out and get them started strongly enough to take the sheets off but leave the robbing screens in place and maybe they'll make it.  Guess time will tell.

[Javin]

My 100 MPH carb has 1/8 in. air screen, and it works wonders. Use the same product and you will get the same result.

http://www.beekeepingforums.com/threads/5223-Robber-screen-moving-screen?highlight=robber+screen

See, here you use 1/8" hardware screen.  I'd used regular screening for like a screen door.  I wonder if the screen itself is the problem.  Perhaps when the robbers land on it, the openings are small enough that they search for the actual opening and find it.  Perhaps the hardware screen is much better since they can see/smell the opening, and even reach through it but not quite make it through.

[VolunteerK9]

I've used the same design as Iddee, only it won't work unless I restrict the entrance on the top of the robbing screen by one bee width. Otherwise, they just rob anyway.

Same thing I do...I leave screens on nucs until they are big enough to transfer to a 10 frame.

[John Pfaff]

I was away for a couple of weeks. When I came back, one nuc had been robbed daily. I even blocked the entrance for a couple of days, still did not stop the robbing. By then they were so weak I thought they were goners.

My last resort was to open the entrance up, let the hive fill with robbers and then sealed the hive for 48 hours. When I reopened the hive, all robbers had become members of the hive. The hive now has a good supply of workers and guard bees that should last at least a couple of weeks. It was an act of desperation.

Later,

John.