I'm in N California where the temperatures are unseasonally warm, 65 degrees day and 38 at night. The bees are flying, probably thinking its spring but there's no food available. I lost 1 strong hive and 2 weaker ones from robbing. I put robber screens on, probably too late, to save the other 5 hives and I closed them in for a week, but everyday robbers keep coming back looking all over the hives for a place to get in. I'm leary of opening the hives for fear of the robbers overtaking the remaining hives. The strong hives have honey and weaker ones are being fed with dry sugar and pollen patty. Any suggestions or comments?
If you have true robber screens on, you can leave them on year round.
If you have moving screens on, you have to eventually allow the home bees to fly.
Robber screens are open at the top to allow home bees a way in and out.
I agree with iddee - if you're using anti-robbing screens, then leave them on all-year-round. I've recently started doing this, and it's proving a much better strategy than fitting them after robbing has started.
With regard to opening hives if robbing has already started - one good strategy is to mist-spray the robbers with water to arrest that activity, then erect a tall wrap-around robbing screen around the target hive:
(https://images2.imgbox.com/c7/37/dMHh4xIm_o.jpg) (http://imgbox.com/dMHh4xIm)
Easy enough to make from thin battens with windbreak mesh stapled to 'em.
LJ
I'm a bit cooler here but not that much than your bee environment. At 60s you can
still feed them syrup. I put in a small 100 watt ceramic light bulb all winter long so that the syrup will not be too cold. If feeding syrup does not work then you have to space the hives further apart. Then reduced the hive entrance to one bee space all winter long. You might have to walk farther to get to the hives though. Moving the weak hives to a friend's house or other location will work too. Then take them back to your home yard once they are stronger.