GENETIC DIFFERENTIATION IN THE QUEEN BREEDING POPULATION OF THE WESTERN UNITED-STATES

Commercial honey bee queens in the United States are produced primaril y in two geographically separated regions, one in the southeastern US and the other in central California. We used mitochondrial DNA and all ozyme variation to characterize 178 breeder queen colonies from 22 Cal ifornia apiaries. Two colonies had the mtDNA haplotype characteristic of Apis mellifera mellifera, the first subspecies known to be introduc ed to the US, and 176 had the haplotype associated with A m carnica an d A m ligustica, the most popular commercially available subspecies. M alate dehydrogenase (Mdh) allele frequencies for the western populatio n, Mdh(65) = 0.65, Mdh(80) = 0.09 and MDh(100) = 0.26, were significan tly different from those previously reported for feral and southeaster n commercial populations. Among the California samples, bees described by apiarists as 'Italian' or 'Carniolan' were significantly different from each other based on Mdh allele frequencies. Five other enzymes k nown to be polymorphic in honey bees were invariant in the California samples. Differentiation between populations in the United States sugg ests they may act as reservoirs for genes that can be useful for bee b reeding programs.