On Aug 25, 2015, at 2:14 PM, Jose Villa <[log in to unmask]> wrote:
What does reality say about each one of these?
1) Defined defense mechanisms of resistance in bees (e.g. hygiene, grooming) make mite populations decrease or not grow significantly in colonies.
Yes, mite resistance has been observed in the field
2) These defense mechanisms are genetically based, such that environmental influences are minor and the traits work uniformly regardless of environment.
This is a non-sequitir. All traits are genetically based but they are all affected by the environment. You cannot separate genes from environment.
3) Life history traits of colonies (seasonal growth patterns, swarming, timing of drone production) give colonies an advantage in dealing with varroa.
This is vague, life history traits can encourage as well as discourage varroa buildup.
4) These life history traits may be more influenced by environment and not as reliable in making colonies uniformly resistant.
As we said, all traits are influenced by environmental factors. No organism exists separate from its environment.
5) Isolation of colonies selects for avirulent mites.
That depends on if avirulent mites exist. In your paper you say "Reduced mite virulence was suggested in one study.” A lot of people have “suggested” it,
6) Crowding of colonies eliminates any advantage of defense mechanisms or life history traits in colonies.
This is Bailey’s hypothesis, that crowding into apiaries is the worst thing for honey bees. And yet, very large apiaries have been common in the past and bees seemed to thrive in them, depending on environment, etc.
7) Outcrossing dilutes the usefulness of different traits at different rates. (This one in itself can be broken down many ways)
This is a very complicated issue. Traits may be beneficial for some things but costly to the organism. For example, if hygienic bees produce less honey, they may survive mites and then starve. Swarming, for example, may propagate the race but be very bad for the individual colony (if it doesn’t find a suitable home and perishes).
* * *
I think these have to be rolled into one question. What is a healthy colony; that is, what are the factors that are most likely to produce bees that can survive.
Whether they can survive only in a particular niche or are adaptable to migratory beekeeping becomes a separate question. Whether these bees can support beekeepers and a beekeeping industry is another separate question.
PLB
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