See http://en.wikipedia.org/wiki/Queen_excluder

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Note added at 54 mins (2008-07-30 15:15:35 GMT)
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Hi Saskia,

I must admit I'm no great expert on beekeeping, but "queen excluder" does seem to fit.

It is the translation given in this glossary of beekeeping terms:
http://home.casema.nl/marten.zeilinga/bijenhouden/dictionary...

This is an image of a plastic queen excluder:
http://commons.wikimedia.org/wiki/Image:Beekeeping_queen_exc...

Is that anything like the koninginnerooster in the DVD?

This is a definition of "queen excluder" found on www.beecare.com:
"The Queen Excluder is a grid of metal or plastic that fits between the Brood Boxes and the Honey Supers; the spaces in the grid allow worker bees to freely pass from the brood boxes up to the honey supers, but the spaces are too small to allow the queen to pass. Therefore, no brood are raised in the honey combs, keeping the combs free for honey storage."
http://www.beecare.com/indexDynFrames.htm?http://www.beecare... :