From reading various messages on this list on the chemical control of varroa, it appears that we are headed into the same dilemma as with antibiotic control of human bacterial diseases - herd resistance. Also, the idea of using chemicals in hives producing food products (honey, pollen, propolis, royal jelly) for consumption seems "unholistic". Are there any research projects looking into biological controls of mites? Paul Cronshaw DC Hobby Beekeeper [log in to unmask]