Other people see this as a very big problem. In fact, it was documented years ago:
"Four heavily Varroa infested honey bee colonies served as "donator" colonies. In distances of 1, 30, 400, 1300 and 1500 m from the donator colonies we placed two mite-free monitoring colonies each which were continuously treated with different acaricides. The "mite free status" was confirmed by the analysis of bee and brood samples. 



Pete,  you missed a VERY IMPORTANT LINE

"In total, 2,029 mites were found in the 10 receiver colonies, but these only correspond to 2.5% of the total mite population in the donor colonies at the start of the experiment. This means that the major part of the initial V. destructor population died together with the collapsed host colonies."


I also take a bit of exception to the loading principal of the experiment.  Its interesting,  but it paints a picture of a single hive surrounded by 4 collapsing hives within a 1.5km range.   

That would correlate to 80% loss,  not 40,  and is pretty unrealistic in most areas,  especially those where hives are dormant in winter.  We all know that most hives lost to Varro are lost in winter due to unhealthy winter bees.

I will grant that a good portion of the US and Randys area have a different picture.  Randy did point out how a small influx of mites from a nearby hive can put you over the "tipping point"   but if your hive was healthy and had good LOW numbers you would still be fine.  Its only when your already close to the edge of the cliff  immigration pushes you off the edge.

It seems to me,  that this issue is a LOT like the pesticide issue.  One or two problems and suddenly a lot of people are using it as an excuse.   Keep your hives in good shape and good low counts and immigration  should be a tiny issue.

Charles


Charles

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