I am in receipt of a report generated by the Bee Mite Informal Meeting held at the Entomological Society of America convention in Baltimore, December 7, 1992. It contains some interesting tidbits that all may not be aware of. Large losses were reported in northern areas where bees were confined for long periods. Tracheal mites did not appear to affect honey production, but did result in decline in number of beekeepers. Although tracheal mites have been known for 100 years, there is no information on what they are actually doing to colonies.
Major suspicions are they pass on viruses and bacteria which do the actual damage to colonies.
Varroa has been found to be involved with organisms called spiroplasms. These can be found in nectar and have been implicated in large-scale dieoffs. In bees infected with spiroplasms, all Varroa associated with them also have spiroplasms. A good many experiments are being carried on with oils and other substances to control populations of both mites. You can now get a two-color decal for your truck, van, shop or production facility.