Agriculture Reference
In-Depth Information
tion, varroa mites can be found everywhere on the planet except Australia. The very
few chemicals that work are used extensively by beekeepers everywhere in the world.
Even the best chemicals do not kill every mite in a treated hive. The survivors' off-
spring had the same resistance to these chemicals. Beekeepers and scientists tried oth-
er chemicals. They increased the dosages, the number of times during the year they
treated, and tried various combinations of chemicals. The mites were unrelenting.
Not every colony of bees perished when attacked by mites. Most, probably 90-plus
percent did, but those remaining would do fine without treatments. But did a colony
survive because it was one of the very few that was resistant to mites or because it was
treated? Honey bees were unable to develop resistance to the mites, as had happened
with
Apis cerana
. So when the chemical
de jour
wore out, the bees continued to die, by
the billions, until new chemicals came to be. The race continued.
There were two developments that broke this cycle. First, scientists working for the
USDA theorized that the bees that had been exposed to varroa mites the longest and
had been exposed to no, or very few varroa-treating chemicals would have had the best
chance to develop some level of resistance to these mites in the population. It turns out
this place was in eastern Russia, where varroa mites and European honey bees had been
in contact the longest, and the beekeepers had the least access to the chemicals used in
the rest of the world. And, when the scientists looked, sure enough, there were European
honey bees living alongside varroa mites and staying alive.
This photo shows a female varroa mite feeding on a pupating honey bee. She will raise
one or two young on a worker honey bee, and two or three on a drone honey bee.
The bees were not a pure race. They were a mix of Carniolans, Italians, Caucasians,
and even some Macedonian stock were present. There were several strains of this mixed
stock. Some were well adapted to the late springs of the area so were very slow to build
in the spring. Others were good honey producers but would build so rapidly that swarm-
ing was a serious problem each spring. Others were defensive, and some were as gentle
as kittens. They were unique in their heritage and they were unique in that most of them
showed good resistance or tolerance to varroa mites. Not perfect, but better than what
had evolved in twenty-five years of exposure in the United States.
Several of the best lines from several locations were developed under the direction
of the USDA scientists and eventually many of these were released to the beekeeping
industry. Soon after a group of dedicated breeders of these Russian lines of bees formed
and developed a quality control and certification program. This gave a great deal of con-
