>[Kerr] succeeded in bringing 62 queens of A. m. scutellata and *one*
>of A. m. capensis alive to Piracicaba. Of these 48 queens from South
>Africa and one from Tanganyika were successfully introduced. ... The
>Africanized bees formed a population which displaced European bees
>...   -- Eva Crane, "The World History of Beekeeping", 1999

------------------------------------------

>Whether or not Africanized honey bees are hybrids or essentially
>unhybridized African honey bees is critical for developing
>management strategies for beekeepers in Africanized areas to cope
>with Africanized honey bees. If hybridization is to be used as a
>management tool, it is important to understand if hybrid bees can
>survive. One way to determine hybridization is to find if
>Africanized honey bees have European honey bee mitochondria. Some
>prior tests have suggested that they do not.
>
>More modern DNA tests, reported in this article, show conclusively
>that many Africanized honey bees do have European honey bee
>mitochondria. This supports using management schemes that rely on
>producing hybrids as a way of mitigating the effects of
>Africanization. Within the past 40 years, Africanized honey bees
>spread from Brazil and now occupy most areas habitable by the
>species Apis mellifera, for Argentina to the southwestern United
>States. The primary genetic source for Africanized honey bees is
>believed to be the sub-Saharan honey bee subspecies A. m. scutellata.
>
>Over 25% of the "African" mt-DNA found in the Africanized population
>in Argentina are derived from non- A. m. scutellata sources.

------------------------------------------

>Twelve years after the arrival of Africanized honey bees to the
>Yucatan peninsula of Mexico, there has been substantial gene flow
>from Africanized queens into domestic populations of European bees,
>and to a lesser extent from European queens into feral Africanized
>populations. Among managed populations, Africanized mitotypes are
>now at higher frequency than their European counterparts. There
>appear to be no significant barriers to hybridization, but African
>genotypes are clearly superior in this environment. These results
>indicate that levels of hybridization will be dictated by
>environment. In the United States, hybridization will tend to favor
>European honey bees.
>
>Honey bees sampled at sites in Europe, Africa and South America were
>analyzed using a mitochondrial DNA RFLP marker. These samples were
>used to provide baseline information for a detailed analysis of the
>process of Africanization of bees from the Neotropical Yucatan
>peninsula of Mexico. Radical changes in mitotype frequencies were
>found to have occurred in the 13 year period studied. Prior to the
>arrival of Africanized bees, the original inhabitants of the Yucatan
>peninsula appear to have been essentially of south eastern European
>origin with a smaller proportion having north western European
>ancestry. Three years after the migration of Africanized bees into
>the area, only very low levels of maternal gene flow from
>Africanized populations into the resident European populations had
>occurred.
>
>By 1998 however, there was a sizable increase in the level of
>Africanization of domestic populations (61%) with feral populations
>having 87% of mitotypes classified as African- derived. The results
>suggest that the early stages of Africanization did not involve a
>rapid replacement of European with African mitotypes and that
>earlier studies probably overestimated the prevalence of African
>mitotypes.

http://nps.ars.usda.gov/publications/

--
Peter Borst <[log in to unmask]>