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Archive for the ‘Science’ Category

by Laura Poppick, Staff Writer | July 17, 2013 02:03pm ET

honeycomb_2The perfect hexagonal shape of honeycomb cells — once thought to be an incredible feat of math-savvy insects — has now been explained by simple mechanics.

Scientists have marveled at the angular perfection of honeycomb for centuries, but none have been able to clearly describe how it forms. Engineers in the U.K. and China have taken a step forward by showing that the cells actually start off as circles — molded by the shape of a bee’s body — and then flow into a hexagonal pattern seconds later. The researchers reported their findings yesterday (July 16) in the Journal of the Royal Society Interface.

“People have always speculated how bees have formed these honeycombs,” said Bhushan Karihaloo, an engineer at Cardiff University in the U.K. and co-author of the study, citing Galileo Galilei and Johannes Kepler as two of the luminaries mystified by the problem. “There have been some incredible, esoteric, even bizarre explanations; [some people] believed the bees had an uncanny ability to measure angles. But it’s actually much more mundane.”

Source: http://www.livescience.com/38242-why-honeybee-honeycombs-are-perfect.html

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Honey bees, which play a key role in pollinating a wide variety of food crops, are in sharp decline in the United States, due to parasites, disease and pesticides, said a federal report released on Thursday.

Download the USDA Report:  USDA_Report_Honey_Bee_Health

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By Ian Simpson

WASHINGTON (Reuters) – Honey bees, which play a key role in pollinating a wide variety of food crops, are in sharp decline in the United States, due to parasites, disease and pesticides, said a federal report released on Thursday.

Genetics and poor nutrition are also hurting the species, which help farmers produce crops worth some $20 billion to $30 billion a year.

Honey bee colonies have been dying and the number of colonies has more than halved since 1947, said the report by the Environmental Protection Agency and the Agriculture Department.

The decline raises doubt about whether honey bees can fulfill their crucial role in pollinating crops that play a role in about one-third of all food and beverages sold in the United States, the report said.

“Overall losses continue to be high and pose a serious threat to meeting the pollination service demands for several commercial crops,” the report said.

Pollination demands have increased so much in recent years that California’s almond crop alone requires 60 percent of all managed colonies devoted to pollination — rather than honey or beeswax production.

The United States is not alone in facing this concern: The European Union moved on Monday to protect its own falling bee population by banning three of the world’s most widely used pesticides for two years.

The Varroa mite, a parasite first found in the United States in 1987, is the single biggest cause of colony loss in the United States and other countries, the report said.

Another main concern is the effect of pesticides on bee colonies. More research is needed to find out how much pesticide exposure bees get and their effects, the U.S. report said. [ … continue reading ]

Source:  http://www.scientificamerican.com/article.cfm?id=honey-bee-numbers-drop

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by Sid Perkins on 27 March 2013, 2:10 PM

sn-bees-thumb-200xauto-16672The electric fields that build up on honey bees as they fly, flutter their wings, or rub body parts together may allow the insects to talk to each other, a new study suggests. Tests show that the electric fields, which can be quite strong, deflect the bees’ antennae, which, in turn, provide signals to the brain through specialized organs at their bases.

Scientists have long known that flying insects gain an electrical charge when they buzz around. That charge, typically positive, accumulates as the wings zip through the air—much as electrical charge accumulates on a person shuffling across a carpet. And because an insect’s exoskeleton has a waxy surface that acts as an electrical insulator, that charge isn’t easily dissipated, even when the insect lands on objects, says Randolf Menzel, a neurobiologist at the Free University of Berlin in Germany.

Although researchers have suspected for decades that such electrical fields aid pollination by helping the tiny grains stick to insects visiting a flower, only more recently have they investigated how insects sense and respond to such fields. [ … continue reading ]

Source: http://news.sciencemag.org/sciencenow/2013/03/bees-buzz-each-other-but-not-the.html

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130327133347Mar. 27, 2013 — Two new studies have highlighted a negative impact on bees’ ability to learn following exposure to a combination of pesticides commonly used in agriculture. The researchers found that the pesticides, used in the research at levels shown to occur in the wild, could interfere with the learning circuits in the bee’s brain. They also found that bees exposed to combined pesticides were slower to learn or completely forgot important associations between floral scent and food rewards. [ … continue reading ]

Source:  http://www.sciencedaily.com/releases/2013/03/130327133347.htm

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soc-bees-mark-flwrsMar. 14, 2013 — Scientists already knew that some social bee species warn their conspecifics when detecting the presence of a predator near their hive, which in turn causes an attack response to the possible predator. Researchers at the University of Tours (France) in collaboration with the Experimental Station of Arid Zones of Almeria (Spain) have now demonstrated that they also use chemical signals to mark those flowers where they have previously been attacked. [ … continue reading ]

Source: http://www.sciencedaily.com/releases/2013/03/130314085103.htm

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Foraging bees prefer contrasting colors rather than stripes when they select flowers

FlowerFlower-colors-said-biggest-bee-draw colors that contrast with their background are more important to foraging bees than patterns of colored veins on pale flowers according to new research, by Heather Whitney from the University of Cambridge in the UK, and her colleagues. Their observation of how patterns of pigmentation on flower petals influence bumblebees’ behavior suggests that color veins give clues to the location of the nectar. There is little to suggest, however, that bees have an innate preference for striped flowers. The work is published online in Springer’s journal, Naturwissenschaften – The Science of Nature.

Very few flowers are a simple block of a single color. Patterns of pigmentation include color patterns within a petal or different colors on different petals. These patterns are thought to be important for pollination. Bees can identify, and are sometimes attracted to, patterned flowers over plain flowers. These patterns can increase the speed with which bees locate the nectar reward in a flower.

Venation patterns – or lines of color on flower petals – are common in Antirrhinum flowers, commonly known as snapdragons. The authors looked at the ways in which these color veins influence bumblebee foraging behavior. They exposed bees who had not seen flowers before to veined, ivory and red types of snapdragon flowers. They observed whether bees could distinguish between ivory and veined flowers and which type of flower they preferred, when they were looking for nectar.

From the bees’ perspective, red flowers reflected little light while red veins on ivory flowers slightly changed the color of the flower. The ivory background, however, had the most effect, as it contrasted with the brown background more than the red flowers did. Bees successfully discriminated between ivory and veined flowers but showed no preference for one or the other. In contrast, both ivory and veined flowers were significantly more popular than red flowers.

The authors conclude: “Venation patterns might be prevalent in nature because they can be useful nectar guides, particularly when they also increase flower visibility. But it appears that the color contrast of a flower with its background has a greater influence on bee preference.”

Source:  ABJ Extra – http://us1.campaign-archive2.com/?u=5fd2b1aa990e63193af2a573d&id=0e44f2645a

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