This one has done the rounds before.
My club has been assessing the benefits of the open mesh floor by using a couple of colonies over solid floors for the Winter/Spring .
We have found these colonies in advance of the rest.
I have over Wintered this year with floors in (put in after oxalic acid treatment)
One colony 2 weeks between inspections in March had drawn comb and filled with brood the space between the bottoms of 14x12 frames and the floor including the depth of a completely empty super which I had placed between floor and brood box.
I had to sacrifice an awful lot of brood in order to sort out the mess created in such a short time , I had delayed removing the super because of the terrible weather we were having at the time.
I won't be using such a super again but I will continue putting the floor insert in after oxalic treatment in future
.
I made my open mesh floors a long time ago ,when the thinking was 'a 2 " space between mesh and insert was sufficient to prevent varroa from climbing back into the colony'.
I often wonder how bees cope with ventilation when on an open mesh floor as instinctively they line up and generate a flow of air though the colony either for evaporation of nectar and more importantly for air conditioning . Remember air pulled through a slot will increase in speed and is more controllable by the bees to their requirements.
We do tend to blindly follow the latest trend without it being fully assessed?
It is worth thinking about and carrying out your own assessments ?.
John Wilkinson