Mike Allsopp wrote: > > Greetings all > > Without getting too involved in the debate concerning the merits of > smaller cell size in the control of varroa, I think that I should report > that the worker foundation used here in South Africa has a > diameter of approximately 4.9 mm - and that so far varroa has > shown itself to be very capable of reproduction in these worker > cells, the short post-capping time of African bees notwithstanding. >Hello Mike, It seems from most i have talked to that the varroa problems are still there at 4.9mm but easier to manage. Would you agree or maybe you haven't seen varroa on say 5.4+mm foundation. > Probably the best source of information on comb building by > honeybees is Randall Hepburn's book "Honeybees & Wax", > published in 1986. In this he reports that the cell diameter of > "natural" African honeybee comb is 4.9 mm, and that the minimum > acceptable diameter is 4.8 mm. Hence, we are using the correct > wax foundation for our bees, they will not accept a smaller > diameter, and the cell size at present does not prevent varroa > reproduction. At 4.9mm the amount of female varroa able to reproduce in a cell is very limited and at 4.7mm varroa is said not to be able to reproduce in worker cells. It is my opinion that A. Melifera could be made to reproduce and thrive on 4.7mm but thats only my opinion and yet to be proven or disproven. > > European bees on the other hand have an average cell diameter of > 5.7 mm (according to Hepburn), but are extremely variable. It would > probably be possible to reduce this considerably (which would also > probably have considerable and negative pleiotropic effects), but > surely not as much as 4.9 mm or beyond. 5.7mm would be on the highest end of the scale according to all the feral comb we have measured. One manufacturer of foundation has comb of the 5.2mm size in the U.S.. Kelly co. offers a 5.7mm comb for honey supers and thats the largest we found in the U.S.. I don't want to offend Hepburn but i would disagree to 5.7mm being average cell diameter for European bees. I looked up average cell size in these books. Encyclopedia of Beekeeping- 5mm average worker cells ABC XYZ of Beekeeping- 825-850 cells to the square decimeter New Hive and the honey- bee Apis melifera scutellata 1000 cells decimter other apis melifera- 857 cells per decimeter All much less than 5.7mm. Sincerely, Bob Harrison > >