African honey bees (Apis mellifera scutellata) are generally more resistant to varroa mites than European honey bees. This resistance may be due in part to such things as the post-capping period of scutellata worker bees being shorter than that of European bees. http://www.researchgate.net/profile/...uth-Africa.pdf. Or due to hygienic behavior or self grooming or nestmate grooming behaviors. (I wonder whether the higher rate of grooming behaviors in scutellata may have arisen as a response to the presence of the ectocommensal bee "lice" (Braula coeca) in the scutellata's native region.) Unfortunately, scutellata also generally exhibit more heightened defensiveness than races of bees from more temperate areas. https://oup.silverchair-cdn.com/oup/...CZBIA4LVPAVW3Q
The desirable varroa resistant traits of scutellata may not be inexorably linked to defensiveness but may simply co-occur with their defensiveness due to linkage disequilibrium. My question is whether the desirable varroa resistant traits can be unlinked from defensiveness through either natural processes or selective breeding. The reportedly gentle strain of AHB in Puerto Rico (http://www.ncbi.nlm.nih.gov/pmc/arti...9/#!po=1.42857) may be an example where this has occurred.
Traits related to defensiveness such as the relatively high ratio of guard bees to foragers in AHB may be genetically undesirable in temperate zones. The relatively high level of secretion of alarm pheromones in scutellata could also be undesirable from a survival standpoint in temperate areas. So, in temperate areas, natural selection may support selective breeding efforts to unlink the undesirable trait of defensiveness from desirable varroa resistant traits in scutellata.