Now only an estimated 2% of the feral honey bee population remains,
and even this
derives annually from honey bee swarms from beekeeping operations.
Practically speaking, the wild
honey bees have become extinct in the United States due to
infestation of the Varroa mite.

Infested colonies will die within 1 to 2 years if the beekeeper does
not take necessary actions against
Varroa mites. ... Delaying treatment can be accomplished if you
monitor the level of Varroa infestation in your colonies.

Treatment is justified only when the economic threshold is achieved.
Economic thresholds are defined
as the pest level that justifies treatment in order to prevent the
pest from reaching damaging levels.
For the southeast Piedmont regionb, the economic threshold has been
determined to be:

mite populations: 3172-4261

ether roll levels: 15-38

overnight sticky sheets: 59-187

http://www.ent.uga.edu/bees/Disorders/Varroa_mites.htm
--

Peter Borst <[log in to unmask]>