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miércoles, 1 de julio de 2015

NATIONAL SCIENCE FOUNDATION - Protecting the honey-bearers .- La protección de los portadores de la miel.............

Hola amigos: A VUELO DE UN QUINDE EL BLOG., hemos recibido información de la Fundación Nacional de Ciencias de Los Estados Unidos, sobre la protección que debe realizarse con las abejas las productoras de la miel.

NSF, nos dice: "Los portadores de miel llegados a principios del siglo 17, llevaron a los Estados Unidos por los primeros colonos europeos. Apis mellifera - el nombre realmente se traduce como la miel de abeja-portador, a pesar de que son más conocidas como las abejas de miel.

Durante los siglos siguientes, que florecieron en el clima templado de América del Norte, tanto éxito se han convertido en una parte integral de nuestra economía agrícola, contribuyendo con más de $ 14 mil millones en los servicios de polinización cada año. Están en camiones a nuestros huertos de manzanos y granjas de arándanos, nuestros campos de calabaza y sandía.
Durante la última década, sin embargo, los portadores de miel han sufrido. Han muerto en cifras alarmantes, colonias enteras colapsando en la ruina. El culpable parece ser un complejo cuarteto de factores :

- nutrición pobre,

- parásitos,

- patógenos

- pesticidas -

y los científicos todavía están descubriendo cómo estas tensiones perjudican a las abejas y cómo se pueden prevenir.

More information..........

http://www.nsf.gov/discoveries/disc_summ.jsp?cntn_id=135470&WT.mc_id=USNSF_1

Ancestors of American honey bees shed light on pollinator health

The team collects hive samples and data on honey bee colonies in Kenya's Aberdare Mountains.
Credit and Larger Version

June 19, 2015

The honey bearers arrived in the early 17th century, carried into the United States by early European settlers. Apis mellifera--the name truly translates as bee honey-bearer, though they are better known as honey bees.

Over the ensuing centuries, they flourished in the temperate North American climate, so successful they've become an integral part of our agricultural economy, contributing more than $14 billion in pollination services each year. They're trucked to our apple orchards and blueberry farms, our fields of squash and watermelon.

During the last decade, however, the honey bearers have suffered. They've died off in alarming numbers, entire colonies collapsing into ruin. The culprit seems to be a complex quartet of factors--poor nutrition, parasites, pathogens and pesticides--and scientists are still uncovering how these stresses harm bees and how they can be prevented.

Could the answers to some of these questions lie in Apis mellifera's African ancestors?

"If we can understand the genetic and physiological mechanisms that allow Africanhttp://www.nsf.gov/discoveries/disc_summ.jsp?cntn_id=135470&WT.mc_id=USNSF_1http://www.nsf.gov/discoveries/disc_summ.jsp?cntn_id=135470&WT.mc_id=USNSF_1 to withstand parasites and viruses, we can use this information for breeding programs or management practices in U.S. bee populations," says Christina Grozinger, director of the Center for Pollinator Research at Pennsylvania State University.

Grozinger was part of a National Science Foundation (NSF)-funded project researching East African honeybees, analyzing the health of bee populations at 24 sites across Kenya. The team included scientists from Penn State, the International Centre of Insect Physiology and Ecology (icipe) in Kenya and South Eastern Kenyan University.

NSF's Basic Research to Enable Agricultural Development, or BREAD, program funded the award. BREAD supports creative, fundamental research designed to help small-holder farms in the developing world. The program is a collaboration between NSF and the Bill & Melinda Gates Foundation.

"The BREAD partnership has allowed NSF to build and fully support international collaborations, as well as innovative proof-of-concept basic research with broad implications for global agriculture," says Jane Silverthorne, deputy assistant director of NSF's Biological Sciences Directorate, which funded the research. "This study continues to provide unique insights into how environmental conditions affect the health of honey bee colonies in Kenya."

In 2010, the team of researchers from icipe and Penn State first discovered the deadly Varroa mite in Kenyan bees. A tiny red beast that attaches, shield-like, to the back of a bee, Varroa feeds on hemolymph (bee blood). It transmits diseases and wreaks havoc with a bee's immune system. The parasite's full name--Varroa destructor--is apt; it is the culprit for thousands upon thousands of bee deaths in North America and Europe.

That research was the first time Varroa was documented in East Africa.

"Since Varroa is the most deadly parasite of honey bees and has decimated populations of honey bees wherever it has spread in the world, it was vital to track the effects of the introduction of Varroa on East African bee populations," Grozinger said.

So the team applied for the BREAD award and began analyzing honey bees across Kenya, studying how parasites, pathogens and viruses were affecting the African bees.

What they found was that--despite Varroa--the African bees were surviving, were tolerating the parasites. The bees did not seem to be actively fighting or removing the mites; instead, they had a higher tolerance for them. Researchers also discovered a link between elevation and Varroa: Bee colonies at higher elevations had higher instances of Varroa. This suggests a bee's environment may make it more or less susceptible to the mites. And since environment is also closely related to nutrition--higher elevations often have less flowering plants, which means less food options for honey bees--improving bee nutrition could be one way to combat Varroa.

The relationship between elevation, nutrition and pathogens needs to be examined further, but Grozinger calls it a "very intriguing" correlation. Increasing the diversity of flowering plant species in a landscape--one way to boost bee nutrition--could potentially help bees help themselves, by increasing a bee's natural ability to tolerate Varroa.

The research, published last year in PLOS One, is just a "first blush" at analyzing African bee populations, said Maryann Frazier, a senior extension associate at Penn State and another scientist on the project.

But she says it's important to study honey bees in other parts of the world, and not just because pollinators are a global resource (in Kenya, honey bees not only pollinate, but provide crucial income and nutrition for farmers and rural families).

"What we're really interested in are the mechanisms that allow them to be more resistant. And then we can use that knowledge to select for those behaviors and physiological traits."

Much about those mechanisms remains undiscovered. Frazier, Grozinger, their Kenyan counterparts and others from Penn State are sequencing whole genomes of individual bees collected from different parts of Kenya; this should allow them to identify specific genes that have helped the bees adapt to different environments and potentially resist different diseases. They're also analyzing whether different hive types--many Kenyan beekeepers use hollow logs or trees as hives--affect honey bee health and productivity.

Other NSF-funded honey bee projects are studying the role of gut microbes in bee health, how bees develop colony-level social immunity and much more: the foundation supports more than 250 current pollinator-related projects, many highlighted in the recent Pollinator Research Action Plan, a national strategy to better understand pollinator losses and improve pollinator health. And ensure the honey-bearers thrive for many years to come.

--	Jessica Arriens, (703) 292-2243 jarriens@nsf.gov

Investigators Harland Patch
James Frazier
James Tumlinson
Maryann Frazier
Christina Grozinger

Related Institutions/Organizations Pennsylvania State Univ University Park

..............

A honey bee, Apis mellifera.
Credit and Larger Version

Elliud Muli, of Kenya's International Centre of Insect Physiology and Ecology, inspects a brood.
Credit and Larger Version
Varroa on brood

Varroa mites, a deadly bee parasite, on drone brood.
Credit and Larger Version
African bee

Apis mellifera scutellata, one of the subspecies of honey bees found in Kenya.
Credit and Larger Version

The National Science Foundation (NSF)
Guillermo Gonzalo Sánchez Achutegui
ayabaca@hotmail.com
ayabaca@gmail.com
ayabaca@yahoo.com
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miércoles, 24 de julio de 2013

nsf.gov - News - Bee Faithful? Plant-Pollinator Relationships Compromised When Bee Species Decline

Removing even one bumblebee species from an ecosystem affects plant reproduction.-

Bumble bee foraging on tall larkspur near the Rocky Mountain Biological Laboratory in Colorado.
Credit: Karen Levy, Emory University

Download the high-resolution JPG version of the image. (3.9 MB)

Photo of field with bagged flowers of tall larkspur

Bagged flowers of tall larkspur, used to assess effects of pollinator removal on plants.
Credit: Karen Levy, Emory University

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Scientist Berry Brosi removes pollen from bumble bees in a field in Gunnison County, Colo.
Credit: Karen Levy, Emory University

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Researchers sample bumble bees in a subalpine meadow in Colorado.
Credit: Karen Levy, Emory University

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Biologist Therese Lamperty holding a bumble bee in a glass tube.

Biologist Therese Lamperty assists with the bumble bee species removal experiment.
Credit: Karen Levy, Emory University

Download the high-resolution JPG version of the image. (4.1 MB)

Close-up of bumble bee removed during an experiment and later released unharmed.
Credit: Karen Levy, Emory University

Download the high-resolution JPG version of the image. (3.3 MB)

Remove even one bumblebee species from an ecosystem and the effect is swift and clear: Pollination is less effective, and plants produce significantly fewer seeds.

This according to research published today in the journal Proceedings of the National Academy of Sciences that focuses on the interactions between bumblebees and larkspur wildflowers in Colorado's Rocky Mountains.

The findings show that reduced competition among pollinators disrupts floral fidelity, or specialization, among the remaining bees in the system, leading to less successful plant reproduction.

"We found that these wildflowers produce one-third fewer seeds in the absence of just one bumblebee species," says Emory University ecologist Berry Brosi, who led the study.

"That's alarming and suggests that global declines in pollinators could have a bigger effect on flowering plants and food crops than was previously realized."

The National Science Foundation (NSF) funded the research; the paper was co-authored by ecologist Heather Briggs of the University of California-Santa Cruz.

"This study shows that the loss of a single bee species can harm pollination and reproduction of all flowering plant species in an ecosystem," says Alan Tessier, program director in NSF's Division of Environmental Biology, which funded the research.

"What's equally impressive is the demonstration of the mechanisms--that the loss of a single species changes the foraging behavior of all the remaining bee species."

About 90 percent of plants need animals, mostly insects, to transfer pollen between them so they can fertilize and reproduce.

Bees are by far the most important pollinators worldwide and have co-evolved with the floral resources they need for nutrition.

During the past decade, however, scientists have reported dramatic declines in populations of some bee species.

Some studies have indicated that plants can tolerate losing most pollinator species in an ecosystem as long as other pollinators remain to take up the slack. Those studies, however, were based on theoretical computer modeling.

Brosi and Briggs were curious about whether this theoretical resilience would hold up in real-life scenarios.

The team conducted field experiments to learn how the removal of a single pollinator species would affect the plant-pollinator relationship.

"Most pollinators visit several plant species over their lifetimes, but often will display what we call floral fidelity over shorter time periods," Brosi says.

"They'll tend to focus on one plant while it's in bloom, then a few weeks later move on to the next species in bloom. You might think of them as serial monogamists."

Floral fidelity clearly benefits plants, because a pollinator visit will only lead to plant reproduction when the pollinator is carrying pollen from the same plant species.

"When bees are 'promiscuous,' visiting plants of more than one species during a single foraging session, they are much less effective as pollinators," Briggs says.

The researchers conducted their experiments at the Rocky Mountain Biological Laboratory near Crested Butte, Colo.

Located at 9,500 feet, the facility's subalpine meadows are too high for honeybees, but they are buzzing during the summer months with bumblebees.

The experiments focused on the interactions of the insects with larkspurs, dark purple wildflowers that are visited by 10 of the 11 bumblebee species there.

The researchers studied a series of 20-meter-square wildflower plots, evaluating each one in both a control state, left in its natural condition, and in a manipulated state, in which nets were used to remove the bumblebees of just one species.

The researchers then observed bumblebee behavior in both the control plots and the manipulated plots.

"We'd literally follow around the bumblebees as they foraged," Briggs says. "It's challenging because the bees can fly pretty fast."

Sometimes the researchers could only record between five and 10 movements, while in other cases they could follow the bees to 100 or more flowers.

"When we caught bees to remove target species from the system, or to swab their bodies for pollen, we released them unharmed," Brosi says.

No researchers were harmed either, he adds. "Stings were very uncommon during the experiments. Bumblebees are quite gentle on the whole."

Across the steps of the pollination process, from patterns of bumblebee visits to plants, to picking up pollen, to seed production, the researchers saw a cascading effect of removing one bee species.

While about 78 percent of the bumblebees in the control groups were faithful to a single species of flower, only 66 percent of the bumblebees in the manipulated groups showed such floral fidelity.

The reduced fidelity in manipulated plots meant that bees in those groups carried more types of pollen than those in the control groups.

The changes had direct implications for plant reproduction: Larkspurs produced about one-third fewer seeds when one of the bumblebee species was removed, compared to larkspurs in the control groups.

"The small change in the level of competition made the remaining bees more likely to 'cheat' on the larkspur," Briggs says.

While previous research has shown how competition drives specialization within a species, the bumblebee study is one of the first to link this mechanism to the broader functioning of an ecosystem.

"Our work shows why biodiversity may be key to the conservation of an entire ecosystem," Brosi says.

"It has the potential to open a whole new set of studies into the implications of interspecies interactions."

-NSF-

Media Contacts Cheryl Dybas, NSF (703) 292-7734

cdybas@nsf.gov
Beverly Cox Clark, Emory University (404) 712-8780

beverly.clark@emory.edu

Related WebsitesNSF News: Where Have All the Flowers Gone?:

http://www.nsf.gov/news/news_summ.jsp?cntn_id=119843
NSF Article: It's Wildflower Season on Mountain Peaks, But Alpine Plants May Soon Miss the Date:

http://www.nsf.gov/discoveries/disc_summ.jsp?cntn_id=124767&org=NSF
NSF News: Where Have All the Hummingbirds Gone?:

http://www.nsf.gov/news/news_summ.jsp?cntn_id=124345

The National Science Foundation (NSF) is an independent federal agency that supports fundamental research and education across all fields of science and engineering. In fiscal year (FY) 2012, its budget was $7.0 billion. NSF funds reach all 50 states through grants to nearly 2,000 colleges, universities and other institutions. Each year, NSF receives about 50,000 competitive requests for funding, and makes about 11,500 new funding awards. NSF also awards about $593 million in professional and service contracts yearly.