Buzz on `Killer Bees' Wanes
Experts note slower, `sweeter' swarms colonizing California
Charles Petit, Chronicle Science Writer
After advancing rapidly into Texas from Mexico in 1990, the
much-feared ``killer bee'' invasion seems to be
losing its sting as it slowly enters southeastern California.
The insects have begun colonizing agricultural and desert areas
east of San Diego. A handful showed up in
Crockett recently, apparently after hitchhiking from Guatemala
aboard a sugar freighter, and were killed by
authorities.
But while the bees are still a concern, experts say they seem to
be losing some of their nastiness.
``The bee is moving pretty much along the path we expected . . .
but it is moving much slower,'' said
William Routhier, a California Food and Agriculture Department
pest specialist based in San Diego. ``The
bees were expanding their range at about 300 miles per year in
Central America. Now it's down to about 40
miles per year.''
Possible reasons include genetic dilution from the high density
of commercially raised, common European
honeybees in the United States; parasitic mites that prey on all
honeybees, which have recently hit those
living in the wild particularly hard; and harsh conditions in
the arid regions of Texas, Arizona, New Mexico
and California that the bees have reached so far.
The bees are descendants of a wild strain of African insects
that escaped an agricultural experiment in Brazil
40 years ago. They tend to be more aggressive than ordinary
honeybees and are blamed for hundreds of
human deaths and widespread losses of livestock in South and
Central America.
But those showing up in California, Arizona, New Mexico and
Texas may not quite live up to their
Hollywood horror-movie reputations.
``They are not the same bees that left Brazil. Everybody
recognizes that,'' said Hachiro Shimanuki, leader of
bee research at the U.S. Agricultural Research Service in
Beltsville, Md. ``The longer they take to spread,
the more hybridized they will get with other bees, and the less
dangerous. I think the bees are almost getting
well-behaved.''
Almost. Despite their interbreeding, three deaths in Texas and
one in Arizona have been blamed on
mass-stinging by the bees. And they could accelerate their
spread once they get beyond the southwestern
deserts. In California, they could still colonize much of the
Central Valley and coastal regions.
After crossing the Colorado River from Arizona into Imperial
County in 1994, swarms of the bees have
made their way to parts of Riverside and San Diego counties,
with 85 confirmed colonies discovered and
destroyed so far.
A mountain range has apparently blocked their way to the coast
near San Diego. They are, however,
expected to make their way into the Los Angeles basin,
eventually arriving at the coast, by migrating through
the low San Gorgonia Pass near Palm Springs.
County agricultural commissioners are prepared to undertake
vigorous education programs as soon as the
bees appear, warning people to be cautious around swarms and to
report them to authorities.
``We've been really aggressive on public outreach,'' said
Stephen Birdsall, Imperial County agricultural
commissioner. ``We've had a few minor stinging incidents, and
people call us when they see swarms. Any
swarm we find, we depopulate it. That's the politically correct
way to say we kill 'em.''
The bees, known more formally as Africanized honeybees, get
their bad habits from ancestors that evolved
in Africa. They are more aggressive in defending hives, chase
perceived enemies farther before buzzing off
to other business, and reproduce more rapidly than ordinary
honeybees, which are derived from European
strains.
Africanized bees tend to be slightly smaller than common
honeybees, but even experts find it difficult to tell
one type from another without genetic analysis. And, while they
are more prone to stinging, their stings are
no worse than those of other bees. The danger comes from the
greater chance that a person or animal will be
stung dozens, even hundreds, of times by aroused colonies.
While commercial beekeepers in Mexico and other Latin American
nations have largely surrendered in the
battle against the new bees and now raise them -- very carefully
-- for honey and pollination services,
American beekeepers are aggressively rooting out Africanized
queens that invade their hives. As a result,
Africanized queens often mate with European drones, further
diluting their genes and their propensity to
short tempers.
``Our beekeepers have learned to live with them around, and to
keep them out of their hives,'' Birdsall said.
BEES MOVING NORTH MORE SLOWLY
Seven years after reaching the United States, ``killer bees''
have slowed their spread. They are confined to
parts of west Texas, Arizona, southern New Mexico and, in
California, Imperial, Riverside, and eastern San
Diego counties. They seem to be losing some of the mean
disposition that gave them their nickname. They
were accidentally released in Brazil 40 years ago.
SOME BEE FACTS:
-- More accurately called ``Africanized Bees,'' they are hybrids
between an aggressive, tropical African bee,
and the more common domestic, European honeybee.
-- They are slightly smaller than European honeybee, but
otherwise appear identical.
-- The bees defend their hives aggressively, sometimes chasing a
person or animal a quarter mile.
-- They produce honey, but are more difficult to handle.
-- If caught in a swarm of stinging bees, run away or find
shelter. Do not swat. Crushed bees release an
odor that incites more bees to attack.
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