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Article #1
Permanent Address: http://www.scientificamerican.com/article/bee-researchers-make-friends-africanized-killer/
Bee Researchers Make Friends with a Killer
Latin America finds Africanized killer bees are better honey producers than expected
By Erik Vance | December 11, 2013
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In the Mexican highlands, nestled between towering cliffs blanketed with verdant
temperate jungle, is the tiny mountain town of Tepotzlan. Home to an ancient Aztec
outpost high in the mountains and inhabited with monkeylike creatures called
coatis, it is the definition of quaint, picturesque Mexico.
It’s also a great place to buy honey. Most honey you buy on Mexican streets isn’t
the genuine article—it is honey-flavored syrup. For the real stuff, you have to go
down a small side street in Tepotzlan and wander around asking for the “mujer de
miel”—the honey lady. Eventually you find her house, a bland wall facing the street, guarded by a
massive angry dog. But inside, her courtyard is friendly, lined with bushy plants and flowers of every type.
The honey lady is thin and elderly but sharp as a tack. Ten dollars buys you the best honey in town and a
few minutes to talk beekeeping.
Bees in Mexico, she says, aren’t what they used to be. Her hives don’t produce like they once did and
entire colonies often fly away before she can even harvest their honey. “The problem,” she says, “is the
Africanized bees.
It’s been almost 30 years since Africanized (often called “killer”) bees first landed in Mexico. It took them
just seven years to take over the country and cause an extended media panic in the U.S. In the end, they
invaded southern states such as Texas and Arizona but were halted by colder winters north of there.
For most of us, the story ends here. European honeybees, favored by most beekeepers in Latin American
and the U.S., however, have pretty much disappeared from Mexico and points south—leading to steep
declines in the collection of honey. Except that’s not the end of the story.
Although Mexico’s honey exports initially dropped by more than 50 percent when the Africanized bees
arrived, production has since recovered to 75 percent of historical levels. During that time the Africanized
bee has built a sort of fan club among many Latin American researchers. “In my experience these bees
are better producers than European ones,” Javier Quezada-Euán, a bee expert at the Autonomous
University of Yucatán, wrote in an e-mail. “[But] it is much easier to blame the bee than the bad
management techniques.” Quezada-Euán and others believe the arrival of the Africanized bee in the
Americas may turn out to have been blessing in disguise.
Accidental invasion
Apis mellifera, or the common honeybee, has dozens of subspecies originating in Africa, Europe and
Asia. The most well known is the Italian honeybee (A. mellifera ligustica), which is found in most U.S.
beehives. It’s a fat, docile bee that stores massive amounts of honey so as to wait out long winters.
Groups of these bees tend to look for the big haul, using complex communication signals to descend on
rich clusters of flowers all at once.
But just as many (if not more) honeybee types come from Africa. In the 1950s Brazilian researchers
brought one of those—A. mellifera scutellata—to a laboratory to help breed a better, hardier New World
bee. But the African bees escaped. These so-called “killer” bees were faster, more scrappy and far more
resilient. They breed fast, are less picky about flowers, and move quickly—abandoning hives and splitting
them like dividing cells whenever they have enough honey. And they defend their hives with a passion.
Far more at home in the tropics than the Italian bees, they swept through 20 countries, moving 300 to 500
kilometers north per year and arguably became the most successful invasive species of the 20th century.
They hit Mexico in 1986 and by 1993 had pushed out the European bee. “The dream of working with
European bees is part of the past, at least for Mexican beekeepers,” says Ernesto Guzman, head of the
Honey Bee Research Center at the University of Guelph in Ontario. “If you want to make comparisons
between then and now, beekeeping was more profitable, the cost of production was lower. It was more
pleasant to work with European bees, there were less stinging incidents.”
And yet the Africanized bees had more to offer than most people realized at first. For one thing, they
groom themselves more often than Italian bees, making them less likely to get sick from mites and other
parasites. For another, they don’t mind the rougher conditions of a desert or rainforest. “The European
bee will just starve to death, the Africanized bee is foraging, bringing things in, and getting by. It doesn’t
give up, it’s not an all-or-nothing kind of bee,” says David Roubik, a veteran bee researcher who has
worked throughout Latin America. In the 1980s he was alarmed at the appearance of the invaders at his
sites in French Guiana and thought it might be the end of the native fauna. But after decades of work he
says the bee may actually be improving the availability of a lot of flowers. He showed that coffee, for
instance, has flourished under these new bees.
He and other African bee lovers say it is not even accurate to call them Africanized bees anymore. After
decades of a massive and uncontrollable continent-wide wild breeding experiment, the African-Italian
hybrid has morphed into a totally new bee unlike either parent species. “It does not look exactly like any
other kind of honeybee that has ever been on Earth,” Roubik says. “The Brazilians know this very well.
And they’re quite happy with the bee that it’s turned into. But it’s been a long and painful road and it was
totally out of control.”
A new five-year project led by Mexico’s National Institute of Forestry, Agricultural and Livestock Research
aims to test this. Rather than lamenting the loss of the fat and lazy European bee or fighting the scary
African one, scientists are trying to breed new varieties of Mexican bees. “They think this is the best thing
that ever happened to them in Brazil,” says Jose Luis Uribe Rubio, a lead researcher in the project who
works out of the northern state of Querétaro. “In biological terms it is a superorganism. In terms of
competition it’s better than the European bees.”
Uribe Rubio envisions Mexican bees that mix the best qualities of African and European bees, each
specifically suited to a part of Mexico. For instance, in the south honey thievery (by humans) is rampant
and many beekeepers prefer a more aggressive African bee that adeptly defends its hive. Places where
mites are rampant, keepers like a bee that obsessively cleans itself. “Once we conclude this program, we
want to have commercial fecund queens that we can send to the southeast or to the coast or the
mountains or to the desert, etcetera,” he says.
Part of this will involve extensive breeding programs (which work better in desert regions than in jungles,
where there are lots of wild bees messing up the gene pool) and part will involve educating beekeepers
and fighting a stereotype that African bees are always bad and European ones good.
To avoid losing hives, beekeepers will have to watch the flowers and harvest the honey on nature’s
schedule rather than theirs. They’ll have to move the hives apart and wear more protective gear. But in
the end, it may result in a better bee—which, ironically, was the reason the African bees were brought to
the New World in the first place.
“We need to come to the resolution and acceptance that this is the kind of bee we have now,” Guzman
says. “That’s it. Period. Let’s work with it—let’s do the best we can do now.”
Article #2
Florida officials use Labrador retrievers
to sniff out the invading snails
Giant African land snails are the size of
rats, eat the walls of houses, and carry a
dangerous parasite called rat lungworm.
OCTOBER 25, 2013
Florida’s Unwelcome Guests
Dogs are the latest weapon in the state’s battle against a seriously slimy invasive species
By Sean Price | for Scholastic News Interactive
As one of America’s top vacation states, Florida welcomes all types of visitors. But giant African land
snails are not among them.
The snails are an invasive species—an animal or a plant that moves into an area and harms native
species. These snails are not like the ones you might find in your backyard. These slimy pests are the
size of rats and can actually eat away the walls of houses. Worse, they can spread diseases quickly and
like to eat about 500 species of Florida’s native plants.
So far, state officials have spent about $6 million trying to get rid of the giant snails. A team of 45 people
regularly spreads out to hunt for the snails, sometimes searching on their hands and knees. They have
also used traps and chemical treatments. And now, Florida officials have called out the dogs—Labrador
retrievers, to be exact.
“They’re very good at detecting the giant African land snail,” said Richard Gaskalla of the Florida
Department of Agriculture. “So we're building four-legged technology into this program as quickly as we
can.”
HOME INVASION
The Florida snail hunt started two years ago, when a homeowner first spotted one of the pests in Miami.
The snails eat stucco and plaster used to make walls. Both have calcium that helps the snails build strong
shells. A single snail can quickly cause thousands of dollars in damage to a building.
But officials are more afraid of what the snails could do in the future. The pests could destroy farm crops.
They also carry a parasite called rat lungworm. This parasite can cause a serious disease
called meningitis, which affects the tissues surrounding the brain.
Dogs are a great weapon against the snails, which have no natural predators in Florida. Canines are
already used to sniffing out all kinds of things: drugs, bombs, missing people, invasive snakes, and even
some types of cancer. The giant African land snail gives off a fairly strong scent that trained dogs can
track.
PAW PATROL
Florida officials think they now have the snails contained in the Miami area. About 128,000 of the
creatures have been found and destroyed. And there has been a big drop in the number of snails found
each week—from thousands to hundreds.
“After two years of battling this invasive and destructive pest,” said Florida Commissioner of Agriculture
Adam H. Putnam, “we are confident that we will win this fight.”
Article #3
A beautiful but deadly predator stalks the Gulf of Mexico
By Austin American-Statesman, adapted by Newsela staff
06.12.14
GALVESTON, Texas — It sounds like something from a horror movie: A beautiful, feathery-looking
species of fish but with venomous spines and a ferocious appetite sweeps into the Gulf of Mexico,
devouring everything in its path.
Unfortunately for the native fish and mollusks it’s eating, this attack isn’t unfolding on the big screen.
News has been spreading of lionfish, a maroon-and-white striped native of the South Pacific that first
showed up off the coast of southern Florida in 1985. Most likely, someone dumped a few out of a home
fish tank. Since then, the fish have swept up the Eastern seaboard and down to the Bahamas, thanks to
very high reproduction rates and no natural predators.
Lionfish now are more common in the Bahamas than their home waters.
Sporting Stripes And Spines
“The invasive lionfish have been nearly a perfect predator,” says Martha Klitzkie, director of operations at
the Reef Environmental Education Foundation (REEF) in Key Largo, Florida. “They’re moving into new
areas and, when they get settled, the population increases pretty quickly.”
The lionfish population exploded in the Florida Keys and the Bahamas between 2004 and 2010. As
lionfish populations boomed, the number of native prey fish dropped. According to a study by Oregon
State University in 2012, native prey fish populations in the Bahamas fell an average of 65 percent in just
two years.
Lionfish first appeared in the western Gulf of Mexico in 2010. Scientists spotted them in the Flower
Garden Banks National Marine Sanctuary, a protected area about 100 miles off the Texas coast. Now
scuba divers spot them on coral heads nearly every time they explore a reef.
“It’s kind of this impossible battle,” says Michelle Johnston, a researcher at the National Oceanic and
Atmospheric Administration in Galveston. “When you think how many are out there, I don’t think
eradication is possible now.”
Lionfish are fascinating and beautiful. They grow to about 18 inches and have numerous venomous
spines. Their stripes are like those of a zebra. They hang near coral heads or underwater structures
where reef fish flourish. They wait for their prey to draw near, then gulp them down in a flash.
The fish mature in a year and females can spawn every four days, pumping out 2 million eggs a year.
They live about 15 years.
Lives Anywhere, Eats Anything
In the South Pacific, predators and disease keep lionfish in check. But here, nothing recognizes them as
food — those feathery spines serve as do-not-touch warnings to other fish. The few groupers that have
been spotted taste-testing lionfish have spit them back out.
In the NOAA Fisheries Science Center in Galveston, Johnston sorts through a rack of glass tubes. Each
one contains the stuff found in the stomach of a lionfish collected in the Flower Garden Banks.
She points to a fish called a bluehead wrasse in one jar.
“This little guy should still be on the reef eating algae, not here in a tube,” she says.
Other jars contain brown chromis, red night shrimp, cocoa damselfish and mantis shrimp, all native
species found in lionfish bellies. “They’re eating young fish that should be growing up. They’re also eating
fish that the native species are supposed to be eating.”
Lionfish can eat anything that fits into their mouth, even fish half their own size. They eat important
species, such as snapper and grouper. They’re eating so much, that scientists say some are getting too
fat.
They can live almost anywhere in the water. They like crevices and holes and can find them on anything
from a coral head to a drilling platform to a sunken ship. Their range seems limited only by temperature —
they don’t seem to go farther north than Cape Hatteras, North Carolina.
“As long as they have something to eat, they’ll be there,” Johnston says.
REEF Reeling Them In
The effects of their invasion could become widespread, scientists warn.
In the Gulf, lionfish are eating herbivores like damselfish and wrasse, which keep the reef clean. “When
you take fish away, coral gets smothered, the reef dies, and we lose larger fish," she says. "It’s a snowball
effect of negativity.”
The only known way to keep lionfish in check here, scientists say, is man.
Scientists don’t want to bring in another non-native fish to eat lionfish, for fear of creating another invasion
problem, Johnston says.
That’s why lionfish fishing tournaments of sorts, are popping up around the Caribbean and Gulf. Locals
are encouraged to kill and gather the fish. In some places, including Belize, they cook them up.
“We’re never going to be able to eradicate lionfish, but there is a level where the population can be
controlled and impacts can be limited,” says Klitzkie of REEF.
REEF has organized lionfish tournaments in southern Florida and the Bahamas. Participants have
removed more than 12,000 lionfish since the fishing series started in 2009.
In the Gulf, researchers like Johnston have special permits that allow them to remove lionfish when they
spot them in the Flower Garden Banks, but they need help. And that takes divers, boats and money.
“It’s really an uphill battle,” Johnston says. “The second you stop, they come back.”
Article #4
Tiny earthworms’ big impact
Invasive earthworms change North American landscapes, for better or worse
BY CECILE LEBLANC 2:54PM, NOVEMBER 9, 2011
Invasive earthworms, like the ones in this bait cup sold at stores,
are spread by human activity such as fishermen dumping live
bait and gardeners using live compost worms near forests.
Invasive earthworms introduced to northern North America
hundreds of years ago by European colonists have changed the
region's forests.
Earthworms have many fans. In 1881, Charles Darwin — the father of evolutionary theory — wrote a
whole book on earthworms. In it, he concluded that “It may be doubted whether there are many other
animals which have played so important a part in the history of the world, as have these lowly organized
creatures.”
Gardeners tend to like earthworms because they mix the soil, loosening it and moving nutrients around.
Earthworms even shred leftover plant parts into smaller fragments eaten by microorganisms. In these
ways, earthworms can improve and enrich the soil, allowing garden and certain crop plants to grow
better.
But many American scientists are coming to view some earthworms as enemies.
In the 1600s, European settlers brought European earthworms to North America. At that time, the
continent’s northern forests had no soil-mixing earthworms. If any had once existed there, they were likely
very different from the European species. And they would have been wiped out during the glacial period
that ended 11,000 years ago.
Today, in these forests, legions of earthworms blend soil with plant scraps like fallen leaves and twigs.
And that mixing has proven disastrous for the complex network of soil, water, plants and animals — the
ecosystem — that developed over thousands of years without earthworms. Since arriving in North
America, invasive earthworms have changed the landscape, assisted other non-native species with
getting a foothold, and competed with native species.
Great Lakes Worm Watch, which educates the public about the problems caused by earthworms, has
recently gone so far as to issue what is effectively a “most wanted” poster for the earthworms. A fact
sheet put out by the group proclaims: “Contain those Crawlers.”
Indeed, plead managers of hardwood forests in the northern and northeastern United States: Keep
earthworms out of our woods.
The dirt on earthworms
The lowly earthworm is nothing short of amazing. “It is a very simple organism,” explains Mac Callaham, a
research ecologist with the U.S. Forest Service in Athens, Ga. And yet, he adds, earthworms have
diversified and evolved, or changed over long periods of time. They live in nearly every available habitat,
spread across every continent except Antarctica. They live high in trees, 10 meters below the soil’s
surface and everywhere in between.
Altogether, scientists have discovered at least 5,000 species and suspect that many more await
discovery.
Though native earthworms most likely were wiped out in northern North America when glaciers covered
the area, other parts of the continent are rich in earthworm species. “We suspect that there are dozens
and dozens, if not hundreds, of undiscovered species,” said Callaham, in addition to the roughly 250
native earthworm species that have been catalogued.
Earthworm species dwell in different habitats and impact their ecosystems in different ways.
All kinds of earthworms fall into one of three main ecological groups. There are earthworms that don’t live
in the soil. Instead, they live just above it, squirming in or just below the plant litter — all of the leaves,
twigs and bark that have fallen to the ground. These earthworms feed on leaves and on the fungi and
bacteria that help break down leaves. Some of these earthworms live even higher up, in trees, inside
decaying wood or piles of plant material that gather between limbs.
Then there are earthworms that travel through the upper layers of the soil. Common in gardens, these
species feed on leaves, fungi and tiny creatures in that soil layer.
Finally, there are earthworms that burrow deeply into the soil, creating permanent channels up to several
meters long. Periodically, they surface for a carryout meal of leaf litter that they’ll carry back down to eat
deep in their burrows.
Killer earthworms
Cindy Hale is a research biologist with the Natural Resources Research Institute at the University of
Minnesota in Duluth. As a graduate student in the 1990s, Hale took a field trip to Chippewa National
Forest in the middle of northern Minnesota. There she saw a changed landscape. Gone were forest floor
plants like ferns and wildflowers and understory plants like bushes and tree saplings that make up the
middle height of the forest. She and other ecologists on the field trip were given a surprising reason for
the loss of the plants and the ecosystem they sustained: invasive earthworms.
To get an idea of the earthworms’ destruction, picture these forests before European settlers — and their
earthworms — arrived in the Great Lakes region around 200 years ago. Leaves, twigs and other plant
debris had accumulated on the forest floor over the years and created a thick layer of what is called duff.
Fungi, bacteria and microscopic invertebrates such as mites slowly broke down this debris. The duff held
moisture like a sponge, nurturing the growth of many understory plants like wildflowers, shrubs and tree
seedlings. Small animals and birds nested and fed on the forest floor and in understory foliage.
When the first European earthworms arrived, they began doing what they always do: munching, mixing
and moving. Some plant litter earthworms munched through the forest floor and its fungi and bacteria.
Burrowing species, like the common nightcrawler, pulled leaf litter down into their holes to finish munching
and mixing. Slowly, earthworms destroyed the duff on which wildflowers, understory shrubs and tree
seedlings depended.
Listing the effects of invasive earthworms on northern hardwood forests is overwhelming.
Before long, says Lee Frelich of the University of Minnesota’s Center for Forest Ecology, “Earthworms
become the dominant living thing that influences the ecosystem. They influence the type of plants that
can grow, the type of insects that can live there, the habitat for wildlife species and the structure of the
soil.”
In one recent study, scientists looked at how invasive earthworms have affected a type of litter-dwelling
mite. Mites help break down a forest floor’s duff and spread fungus spores, the tiny reproductive units
similar to seeds that give rise to more fungi. Today, more than 100,000 mites of more than 100 species
may occupy each square meter of northern forest soil. That may sound like a lot, but this study showed
that in soil free of invasive earthworms, the mites seem to fare better. They were between 72 and 1,210
times more abundant and the number of mite species was one to two times higher.
The potential reasons for this difference reveal a complex soil ecosystem. The earthworms’ soil mixing
might be eliminating the fungi on which mites feed, or the earthworms might be introducing additional
routes — earthworm tunnels — through which other predators could enter the soil and eat the mites.
Jumping earthworms
“Even if the European earthworms don’t scare you, the Asian ones should,” said Hale. These earthworms
are more aggressive, faster-moving and more damaging.
These Amynthas species are among the most reviled earthworms in America. Called “jumpers,” they can
thrash, whip around and jump, clearing a few inches at a time. Introduced from Asia, these earthworms
became established in parts of the United States by the late 1800s. Composters and fishermen use and
sell them.
While scientists and land managers all acknowledge that European earthworms have some positive
features, especially in agriculture, experts don’t want to have anything to do with Amynthas types.
In and around Tennessee’s and North Carolina’s Great Smoky Mountains National Park, “We are most
concerned about the Amynthas species,” says Callaham. European earthworms also live in the area,
along with native earthworms. But the European species appear to do best in disturbed sites — places
where humans have already been moving plants and soil around. This includes agricultural areas, where
the European worms are valued. Amynthas earthworms, by contrast, seem to thrive everywhere.
A 2010 study by Bruce Snyder of Kansas State University in Manhattan looked at native millipedes
andAmynthas agrestis in Great Smoky Mountain National Park. Snyder’s work is among the first to look at
how jumping Asian earthworms interact with a native species.
Both millipedes and Amynthas agrestis live and eat in plant litter, so they potentially compete for food.
Researchers counted how many of each was present in tiny plots of ground. In plots with Amynthas
agrestis, the number of millipede species was reduced by 63 percent and the total number of millipedes
was reduced by 30 percent, compared to plots where there were no jumpers. Snyder hopes to further
investigate why the arrival of Amynthas leads to fewer millipedes.
Humans and earthworms
Earthworms don’t move fast. The leading edge of an earthworm invasion can advance, on average, 10
meters per year. But humans can accelerate the worms’ spread.
Fishermen often use invasive earthworms for bait. Many have introduced invasive earthworms to rivers,
streams and lakes previously unexposed to these animals. Gardeners who use earthworms to create rich
compost for their soil may unwittingly introduce invasive ones. The worms and their tiny cocoons (from
which hatchlings will emerge) even hitch rides in the mud on tires, potted plants and road materials
shipped around the nation.
“They move around as fast as people move them,” said Minnesota’s Frelich. Thanks to people and their
activities, invasive earthworms have now spread throughout the United States and other parts of the
world.
But they’re not everywhere yet. In the Great Lakes region, “20 percent of the landscape is earthwormfree,” says Hale. Of the remaining 80 percent of land, half of the terrain has fewer than two earthworm
species — meaning there isn’t yet too much impact on the ecosystem, she explains. For these regions,
she says, now is the time to take action.
Educating the public, especially fishermen and composters, is one approach to stopping the spread of
invasive earthworms. Identifying which lands are currently earthworm-free is another.
Ryan Hueffmeier is program coordinator for Great Lakes Worm Watch. Along with Hale, he has been
working on a research-based model that will help create large maps of areas with minimal or no damage
from invasive earthworms. Ultimately, landowners can use the model to identify earthworm activity on
their property. Once identified, lands with minimal or no earthworm damage can be targeted for
protection.
But scientists suspect that once invasive earthworms arrive they can’t be removed. And even if all could
be, affected forests might never return to the way they were. “It’s very much a story of learning to live with
them,” concludes Frelich. If invasive earthworms impact native plants, he says, forest managers may
have to learn how to counter the disruptions.
Forest ecologists have called earthworms “ecosystem engineers” because they can modify or create
habitats that otherwise would not be present. Whether this is a good thing depends on the situation.
“Earthworms aren’t good or bad,” said Hale. “What they do and how we value it is what matters. In one
place — farm fields or gardens — we really like European earthworms and what they do, so we consider
them good. In native hardwood forests, we really don’t like what they do — so we consider them bad. You
really have to understand how an organism affects an ecosystem,” she explains. “Things aren’t black and
white.”