Peter Borst mentioned the following as likely reasons for Varroa tolerance 
in African honeybees.
* Short post capping period fails to limit varroa buildup
* African bees have a much shorter lifespan

Peter, What about the fact that AHB swarm much more frequently than EHB 
there by interrupting the brood cycle frequently and making build up of 
varroa more difficult?

Steve Noble

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