>[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]>