Hi all

Regarding natural selection vs breeding, there are some very important principles here that cannot be lightly overlooked. Both Dave de Jong and Mike Allsopp have warned for years that ordinary breeding of bees will not produce mite resistance adequate to the job. Meanwhile, Tom Glenn and others working with the VSH line and Danny Weaver on his own, have developed bona fide mite resistance. 

Why has such resistance not taken hold? Is there something inherently wrong with breeding resistance as opposed to allowing it to develop via natural selection? Of course not. Breeding uses the fundamental principles of genetics just like natural selection, to achieve its aims. Often we breed for other things besides survivability, such as appearance or flavor in food. But ultimately we need varieties that can survive; if they can't they can't even be used. 

So what is the fly in the ointment here? It's there if you look hard enough. VSH lines were tested in Hawaii and were found effective, but only if they were pure VSH. If they were half bred with regular stock (outcrossed), the VSH treat was not effective. The problem is the susceptible stock. It all has to die. Nature would do that, but we don't. Read the following and you will see what I mean:

> Most current day grape rootstocks were and are originally imported from Texas. These were taken from the native wild mustang grapes that grow across Texas. This rootstock also saved France's grape industry in the early 1900s when phylloxera decimated the wine and vineyards of Europe. [note: decimated is the wrong word; wiped out would be more appropriate]

> AxR1 is a grape rootstock once widely used in California viticulture. It achieved a degree of notoriety in California when, after decades of recommendation as a preferred rootstock - despite repeated warnings from France and South Africa about its susceptibility (it had failed in Europe in the early 1900s), it ultimately succumbed to phylloxera in the 1980s, requiring the replanting of most of Napa and Sonoma, with disastrous financial consequences.  

source: Wikipedia, so may contain egregious errors, but the principles are correct

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