An really interesting article from Randy Oliver on mite drift.
Figure 2. From mid-September through the end of November, over 500 mites hitchhiked their way into this continually-treated, mite-free hive (red line); the semi-weekly counts are the black columns. A few weeks prior, I hadn’t detected any mites coming in, so I’d waited until my experiment actually began in mid-September to start inserting stickyboards again. It looks as though I did so a bit late, as mites were already flooding in by then. When I reinserted stickyboards during a rainy period in December (not shown), mite drop in all monitored hives was zero ― indicating that no mite reproduction had been taking place in any of the treated monitor hives.
http://scientificbeekeeping.com/mite-drift-quantification/
Its really makes you think about untreated colonies and how they could move so many varroa in to one of your hives after you have treated them any time of year!
Figure 2. From mid-September through the end of November, over 500 mites hitchhiked their way into this continually-treated, mite-free hive (red line); the semi-weekly counts are the black columns. A few weeks prior, I hadn’t detected any mites coming in, so I’d waited until my experiment actually began in mid-September to start inserting stickyboards again. It looks as though I did so a bit late, as mites were already flooding in by then. When I reinserted stickyboards during a rainy period in December (not shown), mite drop in all monitored hives was zero ― indicating that no mite reproduction had been taking place in any of the treated monitor hives.
http://scientificbeekeeping.com/mite-drift-quantification/
Its really makes you think about untreated colonies and how they could move so many varroa in to one of your hives after you have treated them any time of year!
Let me never fall into the vulgar mistake of dreaming that I am persecuted whenever I am contradicted - Ralph Waldo Emerson