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  • Greased correx sheets for Varroa monitoring -unfortunate side affects?

  • General Q&A, Bee chat and only Bee chat please
General Q&A, Bee chat and only Bee chat please
 #7814  by Yorkbees84
 18 Jun 2020, 13:49
Hi All

I use a correx sheet to monitor varroa drop, usually leaving it 2-3 days when it's fine weather. I grease it lightly to ensure dropped litter sticks and I can observe it easily. However, today I removed it having realised I'd left it on in the rain (just a few hours) and found lots of dead bees on it. Around 50. Never happened before but I did notice prior to putting it on that there were loads more bees walking around on top of the mesh floor (I could see their legs poking through) so not sure if there's a clue in that. All I can think is that after my last inspection on Sunday, when I returned some extracted super frames, honey has maybe dripped down to the lower floor and attracted bees to go beneath the hive then get stuck on the sheet (though it really was only lightly greased). This is all I can think. There aren't dead bees outside the hive and they can't have dropped down through the mesh floor from inside.....Anyone else ever had issues with bees sticking to the correx sheet? Should I just leave the grease off? Anything else that may have caused this? (No signs of obvious disease on the dead bees and not a single varroa mite in site as it happens!).
 #7821  by AndrewLD
 18 Jun 2020, 17:36
Let's not ignore the obvious, returned supers are a magnet for robbing, which is why it is best to put them on in the evening and on all the hives at the same time. If you have done it just out of a flow (June gap?) the air can fill with bees looking for that sudden source of booty. That's the obvious answer.
I would not discard greasing the insert board (I find spray on sunflower oil is really good as opposed to smearing vaseline) but the question is why you are checking varroa right now?
I happen to have insert boards in right now on two hives because I want to exclude varroa as a cause for lots of dead bees in front of a hive (poisoning, CBPV, massive varroa load leading to colony collapse???). Two days is not long enough IMO you need 7 days.
But normally, I check in late March, early April just to make sure a mild winter hasn't left me with a problem that I cannot deal with using a half-dose chemical/Apiguard treatment before the supers are on and given a low varroa infestation (see Defra Guide), I go for the August treatment because I don't want to use MAQ's (if you can in fact buy them right now) and as I have said before - NO Oxalic treatment is currently licenced whilst the supers are on despite what the vaping lobby believe (and I checked the VMD authorization).
So why are you doing it now? Get them off before next week if you are in a part of the UK forecast for a heatwave :)