25 September 2014
Before we
go.
With some
exceptions, bees sting. Bees gather
honey. Honey is a really popular
food. The “honey bear” isn’t just a
children’s story. Because bees sting,
they can sometimes fight off a bear. But
imagine a bee colony in Africa. The
African plains and jungles boast some of the largest, most ferocious and
aggressive animals on earth.
How could a
colony of honeybees survive and keep their food stores – their honey -- in
Africa? By being the most ferocious and
aggressive stinging bees on earth. Say
hello to Apis mellifera scutellata – better know as “the
killer bee.”
If you live
in Europe or the U.S., the bee you saw outside, today, was probably Apis mellifera ligustica – the Italian bee. The Africanized honeybee isn’t a
“cousin” of the Italian honeybee. They’re much more closely related.
In fact, they are different breeds
of the same species, Apis mallifera. If
these bees were dogs, they’d be related to each other as a bull dog is related
to a fox terrier. And, like a bulldog
and fox terrier, these two breeds of bees, the Italian and the African, can
mate to produce a hybrid bee.
Africanized bees are great honey
producers. But, sometimes, it’s hard to
tell whether they’re great honey producers or great honey protectors. “Honey robbers” don’t last so long with
Africanized bees. Beekeepers use the
term “defensive” to describe aggressive bee behavior. And, I suppose from the bees’ point of view,
they are defending themselves. But Africanized
bees take “defensive” behavior to much higher level than other breeds.
This story really begins near a city
named Rio Claro in the Sao Paulo Province of Brazil. There, several colonies of an especially
defensive strain of Africanized bees were maintained by biologist Warwick E.
Kerr.
Kerr was attempting create a new
breed of bee better adapted to honey production in tropical climates. The common breeds of honeybees in the
southern part of North American and all of South America aren’t particularly
good honey producers when compared to U.S. and Canadian bees. Unfortunately, these productive strains of North
American bees don’t thrive in hot, arid or tropical environments.
Careful precautions were taken to
prevent any of these particularly aggressive African bees from escaping into
the wilds of Brazil. The fear was that,
if the reproductive queens and drones escaped, they might begin their own
colonies or mate with local bees to create dangerously aggressive new breeds. Security measures required “extruder screens”
in the Africanized bee hives. These
screens prevent the escape of any reproductive bees (queens or drones) from
the hive.
But, if you’ve ever seen a science
fiction film, you know about “accidents.”
In 1957, a visiting beekeeper noticed that one of the extruders was
interfering with the work of the worker bees and . . . removed the screen. The mistake was almost immediately corrected,
but 26 queens with swarms of workers managed to escape.
Africanized bees are survivors.
The escapees crossbred with local
bees. Colonies of new breeds of bees
developed. The swift and unassisted
spread of the Africanized bees, through South and Central America, made them one
of the most successful invasive species ever known.
By 1985,
Africanized honeybees were found in Southern California. Then, in 1990, they were found in Texas. First discovered in Tucson, Arizona in 1994,
within less than a decade their relative numbers rose from 15% to 90% of the
bee population in the region.
But, if
Africanized honeybees are so productive, why not just keep them and be
happy? The issue with the Africanized
bees is, again, their “defensiveness.”
People are sometimes surprised to discover that, throughout the world,
developers of hybrid bees are trying to create new strains of bees whose only characteristic
improvement is a lack of defensiveness.
Any beekeeper can tell you that handling bees can be extremely
dangerous.
Most people
have seen a picture of a beekeeper draped from head to toe with screen cloth and
other protective garments while covered – literally covered – with bees. But the beekeeper never forgets that those
relatively quiet bees are carrying enough toxic venom to kill dozens of people.
Particular
breeds of bees are valued from their docile disposition. Beekeepers don’t want excitable bees. Figuratively speaking, a beekeeper wants a “calm,”
“level-headed” type of bee rather than a “nervous” bee -- always on the verge
of hysteria.
Even
relatively docile European and American bee strains can suddenly display
extremely defensive behavior. In one
instance, a dog owner routinely tied their pet in their backyard about 40 feet
away from a beehive. After months of
peaceful co-existence, the dog owners came home, one day, to find their dog
suffering with multiple bee stings.
What happened? It’s difficult to say. Something triggered the bees’ “defensive”
behavior. Maybe a threat from another
animal provoked a swarm of stinging bees that didn’t make a distinction between
the threatening attacker and the poor dog who, tied and unable to retreat, was
probably perceived by the swarm as “holding his ground” against them.
Again, in
contrast to common strains of American honeybees, the Africanized bee takes
“defensiveness” to a whole new level.
There is no difference between the venom of the Africanized bee and
American bee. The difference is in the behavior.
Africanized
bees are much more likely to attack with much less provocation than their
American and European counterparts. And,
when Africanized bees attack, they attack in large numbers and are particularly
relentless in pursuit of the “threat.” These bees will follow a retreating person or
animal almost a third of mile before giving up the chase.
The physical
appearance of the Africanized bee increases the potential for trouble. These bees look little different from common
honeybees. Africanized bees are, in
fact, a bit smaller than the typical North American honeybee. You could live, work, or play near a wild
hive of Africanized bees without being able to recognize the threat.
In a recent
incident, a man and woman were suddenly attacked by a swarm of Africanized bees
from a colony known to inhabit a nearby tree.
The couple knew there were bees, but had no idea that these were
Africanized.
In the
nightmarish incident, the woman recounted that suddenly everything became
dark. It took a moment for her to
realize that a giant swarm of bees was blocking the sunlight. The stinging began. Desperate, the couple jumped into a nearby
body of water. But Africanized bees
recognize this behavior and are prepared for it.
After
holding their breath for a few moments, the couple stood up. But the swarm had been hovering over the
water and began furiously stinging the couple.
The pair took a breath and went back down under the water. Then, they raised their faces, nose and
mouth, just above the surface to breathe.
Again, Africanized bees recognize this behavior. When each nose and mouth rose just above the
surface, the bees descended on their exposed faces stinging.
Realizing
their only hope was to reach cover, both jumped out of the water and made a run
for the back door of the house. They
were stung as they fled, but made it inside to safety. As the woman shut the door, she heard
pounding on the door behind her and on windows around the door. It was the bees. A number of them killed themselves as they
impacted the door and windows, at high velocity, in pursuit.
After a 911
call; a visit from Animal Control; and a trip to the emergency room, both
victims were on the road to recovery.
The problem
with Africanized bees isn’t just their appearance. It’s, also, the way these bees spread. Although sometimes Africanized bees establish
colonies in the usual way – a queen bee leads a swarm of worker bees to a new
location – they also use some frankly devious strategies to gain control of
existing colonies.
Sometimes,
an Africanized queen, traveling alone, will enter an established hive of common
honeybees and kill the queen to take her place.
Soon, the hive’s common workers bees find themselves raising a brood of
young Africanized bees. Sometimes, an
Africanized drone (male) bee will mate with a common queen bee outside of the
hive. A new brood of Africanized bees
will be produced by an established hive of common bees.
Of course,
sometimes, a direct strategy is used with the Africanized queen and swarm
attacking an established hive of common bees and driving the hive’s occupants,
queens and workers, out. The invaders don’t
just get a pre-built place to live – the hive.
When they take over the hive, they also take over the honey and pollen
stores accumulated by the old colony.
Although it
is impossible to monitor every colony in the wild, North American beekeepers, routinely,
examine their hives for Africanized strains.
Yes, beekeeper can’t always detect a take-over by Africanized bees –
even in commercially maintained “bee yards” (apiaries). If an Africanized colony is found, it’s
sometimes destroyed (when clearly a threat to a nearby population).
But
beekeepers have some clever strategies of their own. They can remove the Africanized queen and
replace it with a North American queen.
Or, even better, if it is possible to get a North American “laying queen,”
she will begin to lay all the eggs in the Africanized hive. But her eggs will produce a pure strain of common
honeybees.
In some
parts of South America, beekeepers are trying to adapt and use Africanized bee
colonies for honey production. These
bees are very productive, but very dangerous.
Aside from the dangers to beekeepers, themselves, the bee yards
containing these bees must be located far away from human populations. To date, success of the strategy is spotty.
There is irony
to the story of the release of the Africanized honeybees in South
America. At the time of the accident, intense hybrid
breeding projects were ongoing in Brazil.
But these projects involved a different strain of bee. Brazil is home to a bee called
Melapona. This bee is only a modest honey-producer. Yet, efforts were, and are, being made to
increase the bee’s honey production.
What’s so special about the Melapona
bee?
Why is the Melapona of so much
interest to bee breeders?
Well, the development of a good
honey-producing Melapona bee would make beekeeping a lot easier for commercial
beekeepers. The Melapona is one of the
few honey-producing bees that is stingless. The Melapona doesn’t sting at all.
M Grossmann of Hazelwood,
Missouri
& Belleville, Illinois
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