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Scientists and beekeepers search for
ways to lessen the impact of Africanized honey bees on U.S. agriculture
and society.
"They can be almost impossible to work..."
"They killed my donkey..."
"They aren't very scary..."
"They wouldn't let me out of my car..."
"They are a gift from God..."
Who they are, are the Africanized
honey bees - a.k.a. the "killer bees" - and these are
reactions from Mexican beekeepers who have to live with them.
ARS scientists are monitoring the impact of Africanized honey
bees in Mexico, both in the wild and in apiaries, or bee yards;
it's the best way to forecast what U.S. beekeepers will be up
against in coming years.
Although entomologists have always been sure that Africanized
honey bees would nowhere near live up to their Hollywood reputation
as evil villains preying on the public, there has been a major
concern about what Africanized honey bees will do to beekeeping
in the United States.
Originally, the ARS honey bee monitoring program in Mexico was
designed to document the effect of Africanized honey bees on
the
resident population of honey bees. It also provided an early
warning to the United States about when to expect the Africanized
bees' arrival.
But the problems that beekeepers face are common on both sides
of the border, explains William T. Wilson, an entomologist who
heads the ARS Honey Bee Research Unit in Weslaco, Texas.
"Finding ways to manage honey bees when the feral bees surrounding
the area are Africanized is just as important to Mexican beekeepers
as it is to U.S. beekeepers. Mexico simply had the Africanized
bees before we did," says Wilson.
So a cooperative program was created through a memorandum of
understanding between the two countries' agriculture departments.
Wilson not only surveys apiaries in Mexico, he exchanges research
information with his Mexican counterparts on a regular basis.
More informally, he provides advice and management information
to beekeepers.
On a recent surveying trip across the border, Wilson was asked
by a Mexican agricultural official if he had time to discuss
treatments for parasite problems with local beekeepers. When
Wilson agreed, more than 15 beekeepers from the Montemorelos
area showed up for the impromptu session, with just 24 hours'
notice.
Migration of Africanized Honey
Bees
These bees have spread northward
and Southward since their accidental release in Brazil in 1957.
The rate at which they migrate is influenced by many factors
including weather. Approximate migration lines on the map show
that the bees' advance has slowed significantly since 1992. The
area Africanized in 1995 was almost the same as 1994 except in
Southern California.
Beekeeping differs across the border in that it is primarily
for honey production in Mexico, while paid pollination of crops
is nearly as important a source of income for commercial U.S.
beekeepers. "Otherwise, beekeeping is beekeeping,"
Wilson says.
Pollination, and therefore beekeeping, is essential for U.S.
agriculture - about one mouthful of food in three is directly
or indirectly pollinated by honey bees managed by beekeepers.
That adds up to as much as $20 billion worth of fruits, vegetables,
seeds, nuts, and forage to feed livestock every year. In addition,
bees produce about $150 million worth of honey annually.
But, while Africanized honey bees are spreading very slowly through
the southwestern United States since their arrival in Texas in
1990, Mexico has had to deal with them face-to-face for almost
a decade.
In 1988, ARS entomologists William L. Rubink and Wilson, along
with Mexican collaborators, set up a trapline to monitor changes
in the feral honey bee population as Africanized bees moved northward.
That trapline was installed across northeastern Mexico about
150 miles south of the U.S. border.
Since then, several times a year, Rubink and bee lab technicians
collect samples from feral swarms that have taken up residence
in special bee "traps" made of pulp nursery pots, baited
with attractant, and placed in trees about every 2 miles. Big
enough to hold a basketball, the pots are used in pairs joined
at the top, with an opening at each end for the bees to enter
and exit.
The feral population in Mexico became Africanized very quickly.
In 1988, none of the swarms sampled were Africanized; the first
find in the
trapline came in 1989. Less than 2 years later, almost 100 percent
of the bees were Africanized.
Completely unmanaged honey bees are considered feral, rather
than wild, because honey bees are not native to the New World.
The feral honey bees now found throughout the Americas are descendants
from escaped bees brought here by European colonists in the 1600's.
How the Legend Started
These European-descended honey
bees evolved in a temperate climate and did not perform well
in the tropical climates of South America. So in 1956, a Brazilian
geneticist imported African honey bees to Brazil in an effort
designed to improve beekeeping in tropical regions. Some of those
African honey bees escaped and interbred with existing feral
bees, and the hybrid of fear, myth, and legend was created.
In 1992, Wilson and entomologist James Baxter started monitoring
apiaries in northeastern Mexico, taking samples to determine
the effect of interbreeding between the feral Africanized honey
bees and managed bee colonies, as well as checking for the spread
of honey bee parasites. Queens from managed colonies are inseminated
by as many as 17 drones on their mating flights.
Many of these drones can be from feral swarms. So when a surrounding
area is "Africanized," these matings could introduce
Africanized bee genes into managed hives.
Because beekeepers occasionally introduce new queens and can
destroy overly aggressive hives, it was hoped that the process
of Africanization would take longer in managed hives.
"By learning what is happening in Mexico, we get an idea
of what to advise U.S. beekeepers about and what their best management
options will be, once Africanized honey bees arrive in their
vicinity," says Wilson.
To monitor the managed honey bee population, ARS personnel visit
12 to 18 apiaries scattered across the Mexican states of Tamaulipas
and Nuevo Leon twice a year. They gather 10 samples of a few
hundred bees each from the apiaries using a hand-held vacuum
that has been altered to suck up bees instead of dirt.
Because the vibration of the vacuum motor can set off the Africanized
honey bees' well-known temper, the ARS researchers gird themselves
like knights dressing for battle in full protective gear - bee
veil, sting-proof coveralls, and thick gloves. Although the Mexican
beekeepers escorting the researchers to their yards are offered
similar protection, most of them prefer to simply wear the amount
of protection in which they usually work their bees.
"These [Africanized] bees do sting me more. And now I wear
a veil, sometimes even gloves, which I didn't do before. But
they aren't very scary, and I don't need more protection,"
explained Jose Santos Rodriguez, who manages 100 of his own bee
colonies, plus about 1,500 colonies for Apicultura Cardoso, a
commercial bee operation owned by the Cardoso family in Allende,
Nuevo Leon.
When Wilson and his crew started their monitoring in the spring
of 1992, they found that less than 20 percent of managed bee
colonies in Mexico were Africanized - even in areas where nearly
all the feral bee population had been.
Their most current data indicates that today almost all of the
managed hives are Africanized to some extent.
"The process of Africanization of managed yards has gone
much slower than we ever expected without heroic measures being
taken to prevent it," Wilson says. "That's good news
for beekeepers in the United States."
Africanization Does Bring
Change
Africanization is creating
complications, according to some Mexican bee keepers.
Santos says the single largest change has been the problems of
transporting his hives.
"When the bees first started getting meaner, I was moving
them from the citrus orchards to the brush with my truck. I got
stuck on a one-lane bridge waiting to cross, and people along
the side of the road started getting stung. Since then, they
have widened the bridge, and I started using a net over the boxes
to protect people," Santos says.
Moving bee hives between sites reveals another problem of Africanized
honey bees: They are more likely to be honey robbers and absconders.
If they are disturbed too much - as can happen when hives are
being transported - the bees can withdraw all of their honey
from the comb and take off looking for another home, Wilson explains.
"European bees don't leave with their honey like that."
In fact, the only really good thing that Santos can come up with
about Africanized honey bees is that "people who used to
steal some of my honey, don't anymore," he says.
Guillermo Aquiles Cardoso Rodriguez, who heads Apicultura Cardoso,
seconds Santos' dislike for the Africanized honey bees. "It
has been much harder to find workers who will work around these
bees, because some days the bees can be almost impossible to
work with, and some days they are easy."
Cardoso's hives are usually placed in orange orchards so bees
can gather pollen and nectar. "When the bees are there,
I find that no one is working in that part of the orchard,"
he says. "We used to be able to leave the colonies in place
for a long time; now we just put the colonies out when trees
are blooming."
This type of attitude explains another major problem that Mexican
beekeepers are facing: They are losing sites at which to keep
hives. Beekeepers in both Mexico and the United States commonly
seek the permission of landowners to place groups of bee boxes
near concentrations of flowering plants or crops to gather nectar
and pollen.
Noe Jaramillo Navarro, who is a veterinarian and a beekeeper,
as well as the Coordinator of the Mexican National African Honey
Bee Control Program for the state of Tamaulipas, has had to buy
land on which to keep his hives in some cases.
"They [other land owners] are worried now about people getting
stung. They don't want the bees back," Jaramillo says.
Many jurisdictions in Mexico have nearly doubled the required
distance between apiaries and houses and roads. Beehives must
now be 500 feet from neighbors' houses and 200 or more feet from
roads. This has driven several backyard beekeepers out of business
in Ciudad Victoria, where Jaramillo is based.
Jaramillo points out one benefit of Africanized honey bees. "When
the bees came, it forced beekeepers to organize. That's when
the government took the lead in helping to create training to
improve the honey industry." As program coordinator, Jaramillo
holds courses for beekeepers on how to manage honey bees. Topics
include Africanization, diseases, and parasites.
"Unfortunately, some beekeepers cannot afford the safety
equipment and treatments for disease. They go out of business,"
Jaramillo says. "But more new beekeepers come into the business,
and we teach them how to do it well."
Hardest hit have been those who are referred to as rustic beekeepers.
These are rural Mexicans who make bee boxes out of hollow logs
and capture feral swarms from the wild to produce a small but
important income by selling honey. Many are very poor and among
those who find equipment too expensive.
"Also, for a long time after the Africanized bees came,
the government discouraged people from capturing swarms and keeping
them in their backyards, because the feral swarms are the most
Africanized and get riled up and sting people," says Jaramillo.
"That drove a lot of the rustics out of business."
Rustic beekeeper Tomas Arriaga still keeps his bees within a
few feet of the stick, thatch, and tarpaper hut in which he and
his wife live near Hidalgo, Tamaulipas. The increased number
of stings on his hands that he began to get, once his bees were
Africanized, does not bother him.
"But the bees keep absconding," he says. "Then
one swarm killed 10 little chicks plus the hen, and they killed
my donkey. That swarm absconded, but I never messed with it.
I was glad to see it go."
Livestock being killed by bees is one of the biggest problems
for the public and for beekeepers. Many animals are closely confined,
either enclosed by fences or staked out on ropes to graze. Confined
animals cannot outrun attacking bees, and horses, cows, pigs,
and donkeys have all been stung to death. The beekeeper is held
responsible for the cost of any damage or loss.
Beekeepers say they even occasionally end up paying for an old
horse or cow that someone purposely put too close to a bee yard.
For the most part, though, the Mexican public has become used
to living with Africanized honey bees.
"There was a lot of panic and many phone calls in the beginning,"
recounts Juan Francisco Rios Aguilar, who is Coordinator of the
Mexican National African Honey Bee Control Program for the state
of Nuevo Leon. "When people would see any swarm, they would
immediately call for help, especially in the big cities like
Monterrey."
Though he originally set up a program to train and equip volunteers
in each town to deal with swarms, that program has ended.
"Many of the volunteers we trained started out willing to
capture swarms, but after they dealt with a few, they got into
trouble and were stung," Rios says."The police chief
in one town told me he could send two men to get the worst criminal
in town, but he couldn't get eight people to go after a swarm.
Today, most calls for removing a swarm are referred to local
brigades of beekeepers, agriculture department personnel, or
fire fighters. In Mexico City and Guadalajara, an average of
10,000 feral swarms are eliminated each year - most of them Africanized.
More Than Just Temper Problems
Africanization is not the only
problem that Mexican beekeepers have been facing. Two years of
drought have severely limited honey production. Tracheal mites
have spread to honey bees in northeastern Mexico from the south,
and varroa mites have spread from the north.
Wilson was the first to find tracheal mites in Mexico during
a sampling trip in 1980. These mites cause millions of dollars
in losses annually in both the United States and Mexico. Wilson
and other ARS scientists developed a menthol treatment to kill
tracheal mites that is being used in both countries today.
The participation of Mexican department of agriculture officials
and beekeepers in field trials of the menthol treatment allowed
that treatment to be developed more quickly.
Some Mexican beekeepers see the presence of the Africanized honey
bee as a great benefit, a "gift from God," because
they believe the hybrids are more resistant to tracheal and varroa
mites.
Wilson and other researchers have been testing this hypothesis.
"We haven't seen any evidence that Africanized bees are
more resistant, but the jury is still out." Wilson said.
It is possible that there is more resistance to tracheal mites
simply because of survival of the fittest. "Mexican beekeepers
often cannot afford expensive chemical treatments," Wilson
explains. "The bees that survive naturally will have more
resistance."
Wilson and visiting ARS scientist Frank Eischen are also investigating
natural products that are readily available in the wild that
could be used to treat varroa mites.
"We need something less expensive than the chemical treatments
on the market now for both U.S. and Mexican beekeepers,"
says Wilson.
SAMPLING WITH A BEE-VAC
When ARS scientists
began their monitoring of apiaries, beekeepers in Mexico were
leery about letting them gather samples.
"We take 10 vials of bees from each yard that we visit,
with about 200 bees in each container," says Wilson. "To
some of the beekeepers, that looked like we were taking too many
bees from their hives. After all, when honey production is the
main goal, every bee means a little more honey and, therefore,
money."
But Wilson persuaded many beekeepers that it was important to
participate in the monitoring of hives for Africanization and
the presence of diseases and parasites.
Taking samples involves using a souped-up handheld vacuum to
suck bees directly off a frame from the hive box. A plastic tube
replaces the vacuum's conventional snout, and a plastic cup filled
with alcohol replaces the dustbag.
"We modified this contraption ourselves, and we carry about
10 of these bee-vacs on each trip," says Wilson. ''I wonder
what the maids in the hotel think when they see all of them lined
up, recharging, in our room?"
- By J. Kim Kaplan, ARS.
The cooperation of Mexican officials and beekeepers also allowed
entomologist Anita Collins, then in charge of the Honey Bee Research
Unit at Weslaco and now with the ARS Bee Research Unit at Beltsville,
Maryland, to test chemicals that might repel Africanized honey
bees from humans.
"We were looking for something that beekeepers and people
who might have to deal with Africanized swarms could carry with
them," explains Collins. In infested areas, meter readers,
outdoor machinery operators, and even hikers could find a repellant
a useful item to carry.
The most effective chemicals from Collins' tests were all common
mosquito repellants: DEET, dimethyl phthalate, and 2-ethyl-1,3,-hexandiol.
But they all had to be sprayed in a fine mist directly on the
bees to deter them. "Just spraying your clothes didn't do
any good," Collins says.
The Texas Situation
The first Africanized honey
bees were found in Texas in 1990. Now, almost 6 years later,
the feral bee population there is highly Africanized, though
still less than 100 percent.
But Texas beekeepers are now having to deal with the intrusion
of Africanized bees in their apiaries.
"I'm wearing gloves now all the time, when I used to handle
bees with bare hands,'' says William Vanderput, who owns Magic
Valley Honey and Pollination in Pharr, Texas. ''The Africanized
bee is unpredictable; you don't know when or what provokes it.
These bees are moody."
And Africanized honey bees have increased his costs about 20
to 25 percent. "We are requeening more often with virgin
queens to keep
Africanization to a minimum. The first generation isn't that
much different from the Europeans; but after that, if you haven't
requeened, they get really mean," he explains.
Requeening is still the best way to maintain European honey bees
in managed colonies in Africanized areas, according to Wilson.
"To survive in beekeeping today, with all of the troubles
like Africanized honey bees and mites," says Vanderput,
"you really have to love it. It can't just be a business."
- By J. Kim Kaplan, ARS, with special thanks to Weslaco
laboratory technicians Raul Rivera and Jesus Maldonado for translation
services.
William T. Wilson is in the USDA-ARS Honey Bee Research Unit,
2413 East Highway 83, Weslaco, TX 78596; phone 210-969-5005,fax
210-960-5006.
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