The major problem with correlating the two methods is that they measure two
different things. The alcohol wash measures the number of mites per 100 bees
and the natural drop measures the number of phoretic mites in the hive.
Consider two hives, A and B. A has 20,000 bees and B has 10,000 bees. Both
hives have 1000 phoretic mites. Suppose that 1% of the mites die each day.
1) Hive A will give an alcohol wash reading of 5 mites per 100 bees. Hive B
will give an alcohol wash reading of 10 mites per 100 bees.
2) Hive B will give a natural drop of 10 mites per day. Hive B will also
give a natural drop of 10 mites per day.
It is clear that you can not compare one method with the other unless you
account for the number of bees in the hive. In fact, if you use both methods
at the same time, you can calculate the number of bees in the hive!
Best regards
Donald Aitken
***********************************************
The BEE-L mailing list is powered by L-Soft's renowned
LISTSERV(R) list management software. For more information, go to:
http://www.lsoft.com/LISTSERV-powered.html
Guidelines for posting to BEE-L can be found at:
http://honeybeeworld.com/bee-l/guidelines.htm