This is something I copied from another site,found it interesting as I have seen this discussed here previously-----------
Scientests in the ARS Beneficial Insects Research Unit at Welasco,Texas,have found that a strain of the fungus Metarhizium anisoplias is deadly to varroa mites. Parasites known as varroa mites infest honeybee colonies,sucking blood from the bees causing weight loss,deformities,diseases and reduced lifespan.Thes mites which can nearly destroy an entire colony within a few months,now infest honey bee colonies across most of North America.This potent fungus,which also kills termites,doesn't harm bees or affect thier queen's production.To test it,the scientists coated plastic strips with dry fungal spores and placed them inside the hives. Since bees naturally attack anything entering thier hives,they tried to chew up the plastic strips,spreading the spores throughout the colony.
In field trials,once the strips were inside the the hives,several bees quickly made contact with the spores.Within 5 to 10 minutes,all the bees in the hive were exposed to the fungus,and most of the mites on them died within 3 to 5 days. The fungus provided exellent control of varroa without impeding colony growth. "Beekeepers are very edgy about using fluvalinate and coumaphos and are eager to see this natural contol get to the market." "Metharhizum gets the job done and we don't have to worry about varroa becoming resistant to the fungus" Walker A. Jones is in the USDA-ARS Beneficial Insects Research Unit,2413 E. Highway 83, Welasco TX 78596;phone(956)969-4852 fax (956) 969-4888.
Seems promising huh?http://www.ars.usda.gov/research/publications/publications.htm?SEQ_NO_115=140685