> The take home message to me is to be consistent as to where you take your > samples, and not to place too much faith in any single sample. good advice Randy! An interesting discussion and one which is especially needed in presentations at meetings involving new beekeepers. Too many of the so called experts toss out numbers on varroa which beekeepers take to heart without considering the points made in the BEE-L discussion as too the unreliable aspect of testing for varroa load . Because only a few on the list are commercial I will add the most common commercial view point I hear and use myself. The first is most of us feel based on years of dealing with varroa that two treatments a season will be needed in the U.S.. *if* we can pass on a treatment or load of syrup then it really helps the bottom business line. Doing so always has risks (personal experience) . Varroa math is quite simple and as I work hives I see the varroa population grow each week after the last treatment based on observation, rolls and removing pupa. The last time I was able to only treat once a year was when apistan and checkmite were producing 98% kill fast. Today I am resigned to a couple treatments a year. Have found it necessary to treat at least twice a year since 2000. note: Before Medhat might come on saying I am *perhaps* wasting money I need to point out that I have seen virus issues raise its head now when varroa is not kept under *tight* control. Was not so years ago. Too control virus issues today my opinion is we need as low a varroa population in hives as possible AND in my bees this can not be accomplished with a single varroa treatment per year. I applaud Canada for the IPM but there are risks involved *in my opinion*. Canada *is* different in the fact that their season for bees brooding is much shorter than in the U.S. and especially the U.S. south. Testing for varroa is primitive but all we have to work with. The reason testing only a single hive in a yard is not wise. I stick with my prior post and say to test a percentage of the largest population hives and *if* you get a high reading with even *one* then treat the whole yard. Although subject to the lists criticism I will share my fall method of testing. Once the supers are off and before brooding stops I check each hive for brood several times before winter. The reason I want to find the *dinks* (queens with poor patterns, drone layers and queenless hives) as medicating and feeding for winter these hives cost me more money than treating for varroa. I take my rolls from these brood frames as the rolls are from the brood area and we are checking close for queens. Getting rid of *dinks* in the fall is a smart move in my opinion so I take the time to cull. Fall culling is common and I have seen as many as fifty percent of hives depopulated before trucking into Texas. Fresh spring splits with new queens are better in my opinion than hives headed with below average swarmy queens from the year before. I rarely see an over threshold hive in my bees as my varroa controls are always done on time. Already finished for this season for those which in my area with have not yet started. I guess I will repeat again what was told to me by the virus researchers in the U.K. ( Ball & Carrick) and Dr. Shiminuki; "Control varroa levels and you will keep virus issues at a minimum" The hobby beekeeper can risk varroa problems and may not be as aware as I am of the effect a poor control last done ( fall or spring) on the next treatment. Get a poor kill with a low efficacy and the next treatment will need done sooner and *perhaps* if waiting to treat by the calendar* all hives will be over threshold. my 2 cents worth. bob *********************************************** 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