Hello All,
I received an update  tonight from David Westervelt of the Florida Dept. of Ag Apiary inspection department. 
The Florida inspection department finished checking the hives I posted about Dec. 2, 2001. I will share the departments findings with the list.
Quite a large number of hives are involved. These hives were in Maine but now are back in Florida for the winter. 
Quote from David:
"The mites/bees that  were used in this test had only been treated  with Checkmite strips,1 strip in each hive for 42-45 days  1 time    a year. No other treatment for mites the last 3 years".
Bob added:
Although the above is on minimum level  of label instructions I know many commercial beekeepers treating as above. Coumaphos  is not to be taken lightly. You can always use less of a product but not over the amount on the label without being in label violation. .
David quotes;
"We did find that the mites (varroa) had become harder to kill or resistant somewhat. We had planned to start looking at mites in the spring to see if resistance was starting but like normal the resistance  showed up first"

David gives two possible reasons about "Why Florida again":

1. Because we got the strip first?
             Bob comment:

             I agree with Dave!  Was bound to happen. Some researchers  will say the low dose caused the problem but I believe even those dosing with coumaphos twice a year and  with those using two strips a double hive body hive  will see coumaphos resistant mites before long.  

2. Because Florida inspectors were looking for problems:

Again I agree with Dave.  If you don't look you don't find the problems.  I stood up at bee meetings and said I was seeing fluvalinate resistant mites for about three years.  Then about half the beekeepers stood up and said "We treated with Apistan per label and all our hives  are dead  from varroa" 
The best method in my opinion is testing each hive (as per Dr. Delaplane) and treat only those hives approaching threshold. I would recommend to all beekeepers using Checkmite to start looking for coumaphos resistant varroa. 
I tested every hive for the three years after I found fluvalinate resistant mites but have dropped the procedure the last few years. I am planning on going back to the resistance testing program with every hive this spring.
Dave also said he believes all beekeepers and researchers in the world need to share information to solve the varroa problem. I agree completely!
Dave's advice on the resistance problem:
"We need to inform beekeepers that we have found mites that are becoming resistant to Checkmite. Beekeepers need to make sure they do a pre & post treatment mite check . If they start finding mites in the post treatment they need to start looking for other treatments"
 I thank Dave for his work in helping beekeepers and like Dave believe the information helps the most when delivered directly to the beekeepers which desperately need the results of Dave's work. I respectfully post the above with Mr. David Westervelts permission and hope the above meets with his approval. Dave is very busy and I have spent a few hours on the post myself. If other researchers want to email me research information they believe  would be of interest to the Bee-L list I would be happy to post in my name to protect your privacy. I will not reveal the source and only say the information was sent to me. Others on the list will comment for AND against the information  and maybe the comments will help with your research WITHOUT putting your reputation on the line.
Sincerely,
Bob Harrison