From the USDA Agricultural Research Service quarterly report for April-June
2000, which was just published on the Web:

   Beekeepers who want to replace aggressive, defensive African queens with
gentle, easily managed European ones may face a little-known disadvantage, an
ARS scientist and University of North Carolina co-researcher have discovered.
   Within only 1 week after their queen dies or is removed by beekeepers,
Africanized worker bees—which are female—can produce their own viable eggs
for requeening the hive.
   That gives the Africanized bees a headstart in the battle for hive rule,
because European worker bees’ ovaries can’t start producing eggs until the
queen has been missing for at least 3 weeks. Queenless Africanized workers
that have developed ovaries and are laying their own eggs are less likely to
accept a new European queen—and may attack and kill her.
   New experiments, however, may yield tactics to undermine the Africanized
bees’ competitive advantage. The 1-week time frame was already known to occur
in Cape bees of South Africa, but it had not—until now—been reported for
Africanized hives in the Northern Hemisphere. Africanized bees, which sting
more readily then their European counterparts, have invaded Arizona,
California, Texas, New Mexico, and Nevada.
ARS Carl Hayden Bee Research Center, Tucson, AZ
Gloria DeGrandi-Hoffman, (520) 670-6380, ext. 105, [log in to unmask]