When I was a kid walking in the yard with clover blooming almost guaranteed you would get a bee sting. Now if you see a bee on the clover it is a blessing.
Here is a bit of the history of the mites.
More than 300 years after the initial introduction, a beekeeper also imported honey bees (and a very serious problem), perhaps from Brazil, despite a quarantine that had existed for several decades. That person was not the first to break the quarantine; all too often the quarantine had been ignored by others hoping to "improve their strain." Unfortunately, this time the imported bees harbored a voracious parasitic mite,
Varroa jacobsoni, soon to populate all contiguous states and Alaska.
In September, 1987, colonies in some hives transported from Florida to Wisconsin experienced colony failure - the first recorded case of Varroa infestation in this country. A spot check around the nation that Fall revealed the presence of Varroa mites already in a dozen states.
The Varroa bee mite (
Varroa jacobsoni) was first discovered by A.C. Oudemans in 1904, as a parasite of the Asian honey bee,
Apis cerana. In the late 1940s, Through movement of the western honey bee,
Apis mellifera, colonies into and out of Asia, Varroa mite became established on honey bees first in Africa and then in Europe. Quickly, it spread around the world. It was first detected in the U.S. in 1987; Mexico and Canada quickly closed their borders to U.S. bees. Varroa has now been in the U.S. for over two decades and a robust history exists in a number of formats.
One reason the mite is so damaging is that it is relatively new to the Western honey bee (
Apis mellifera). Most parasites have evolved mechanisms so that they do not kill their hosts, in the long range disadvantageous. Thus, the original host,
Apis cerana, is somewhat resistant to predation by mites.
However in temperate areas, almost every Apis mellifera colony infested by Varroa will be killed unless there is intervention to reduce the mite population. There is mounting evidence, however, that certain European honey bees and other populations might be somewhat
resistant/tolerant and incipient breeding programs exist to cultivate and enhance this trait. At the moment the
Russian Honey Bee Breeding Program and those based on removal of mites through
colony hygiene are the most promising. Read contributor Randy Oliver’s ideas on the possibility of breeding honey bees
more resistant to Varroa now and in the future.