Mike Over the last month there have been several contributions on BEE-L describing non-chemical varroa controls: Apr 4 Re: Natural products... Apr 28 ANP comb report Apr 28 drone comb method Apr 28 Reference s re drone method May 3 Mite attractants A simpler drone comb method was used by Dr Tibor Szabo at Guelph Ontario (see ABJ Dec 1994 p 838): Day 1: he placed a frame without foundation in position 3 of the brood nest of ( strong) colonies. He placed another comb at day 7 and day 14. Each week from day 21 on, he removed the oldest (day 1) comb and replaced it with another empty frame. The colonies rapidly built drone comb and it was filled with varroa-attracting drone larvae (10:1 worker). These combs of brood were removed and disposed of (they could have been frozen to kill the mites, then thawed and replaced). Up to 12 combs per hive were removed (in itself a drain on the colony's, and the beekeeper's energy) but varroa population remained low. There are many combinations. It would be nice to see an analysis of cost and labour for them. I noticed beside the article on ANP combs (ABJ Feb 91, p 119 (which indicate a reduction in varroa reproduction when using larger diameter worker cells), an ad. for small cell size foundation by Dadant, referring to USDA research from Tucson, that a small cell size may be effective in controlling parasitic mites. I had not heard of this research. Does anyone know the basis for the statement? Kerry Clark, Apiculture Specialist B.C. Ministry of Agriculture 1201 103 Ave Dawson Creek B.C. V1G 4J2 CANADA Tel (604) 784-2225 fax (604) 784-2299 INTERNET [log in to unmask]