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Sunday, 24 October 2010
Superior beeing - Article - TES Connect
Superior beeing
Article | Published in TES Magazine on 17 June, 2005 | By: Ben Aldiss
Section:
Article
Ben Aldiss describes the life cycle of one of the planet's most useful insects
If there is one creature teachers would like their pupils to emulate, the honeybee must be it. And is it any wonder? There is a lot of truth in the saying, "as busy as a bee". Tirelessly buzzing from flower to flower in its unceasing, selfless quest for pollen and nectar, this marvel of evolution keeps going from dawn to dusk. Imagine what we could achieve if children were as highly motivated.
Honeybees are not the only kind of bee. Like wasps and ants, bees belong to that large and successful group of insects known as Hymenoptera. The name means "membranous wings" and refers to the insubstantial nature of the four small wings that do the seemingly impossible job of keeping a bee airborne.
All ants live in colonies and have a complex community structure, but only a small proportion of wasps and bees are social. Of the 250 species of bee in Britain, just 30 are social - the others lead a solitary existence, during which they meet only to mate. The difference between bees and wasps is simple: bees are herbivores, feeding their young on pollen and nectar, while wasp grubs eat freshly killed flies and other insects.
Among our many solitary species, the mining bees are conspicuous as they emerge from their burrows in sunny banks and earthen paths as the first spring sunshine warms the ground and the early flowers open. Our commonest species, the tawny mining bee, is a rich reddish brown colour and quite furry, like a small bumblebee. The female excavates a shaft in the soil, and creates a series of small chambers at the bottom, then stocks it with masses of pollen scraped from the long fringes of hairs on each of her hind legs. She spends the day visiting flowers to gather this protein-rich food and unwittingly pollinates the flowers in the process.
As she goes from bloom to bloom she sips nectar with her pointed tongue and stores it in an expandable part of the gut called the crop or honey stomach. This not only ensures she has enough energy to fuel her busy life, but the excess is later regurgitated into the chamber along with the pollen, to provide enough nutrients for the entire development of the offspring she will never see.
Such mass provisioning marks a crucial difference between solitary and social insects. It has the advantage that the bee needn't expend any energy in caring for its young, but there are huge risks - despite being tucked up in a secure nest chamber, the abandoned grubs must fend for themselves, a flaw that has been exploited by other bees.
Nearly every one of the 60 kinds of mining bee has a sinister alter ego - an unrelated species that watches its every move as it labours to prepare its nest site. The moment a chamber is finished and the mining bee has laid an egg in the mass of pollen and nectar, the so-called homeless bee makes its move. As the mining bee sets off to collect food for the next chamber, the homeless bee darts down the tunnel and deposits its own egg next to that of its host. What happens next is very simple. The egg of the parasitic bee hatches more quickly than that of the mining bee, and the young grub quickly eats the other egg before feasting on the banquet of nectar and pollen. This strategy is hugely successful. Emerging as an adult female the following spring, all the homeless bee has to do is mate, then lie in wait a safe distance from the nest of its host, while the mining bee does all the hard work.
Before your pupils get ideas of transferring this principle to homework, perhaps you should point out that there is always a downside. Whereas the mining bee can shelter in its burrow, the homeless bee is vulnerable to attack from predators, being out in the open all hours of the day and night. Not surprisingly, many are killed. However, evolution has gone some way to minimise the risks. The outer skin - or exoskeleton - of the homeless bee is thicker and harder than that of its host, making it more difficult for the jaws of a nocturnal predator, such as the ground beetle, to penetrate, and it is also more brightly coloured, with bands of black and yellow. This makes the bee look like a wasp, putting off its most likely daytime predators, birds.
Carpenter bees make their burrows in wood, and these include the familiar leafcutter bee. You may be thinking this is not particularly familiar - the bee itself is not very conspicuous - but its handiwork can be seen on any rose bush from June onwards. If you've ever wondered what those neat curved cut-outs in the leaves are, the mystery is about to be solved. Whereas most carpenter bees line their wooden burrows with a sort of saliva that dries to a rice-paper consistency, the leafcutter makes honey-pots out of leaves intricately glued to make water-tight barrels. A stack of six to eight of these is fitted snugly into the tunnel, each having been provisioned with pollen and nectar and provided with a close-fitting lid to protect the developing egg inside. What is so remarkable is the precision with which the bee cuts the leaf to make the sides of each container, having already cut a perfect circle to fit the bottom. An equally perfect circle is used as the lid, so no leakage of the contents occurs.
Bumblebees have been in the news recently, as their numbers have drastically declined in the past few years. This is undoubtedly due to the reduction in wild flowers and the increased use of insecticides on agricultural land. In East Anglia alone, more than 11,000 miles of hedgerows were removed between 1947 and 1985 to make room for more crops.
Not only did this destroy trees and shrubs necessary for mammals and nesting birds, but all the associated flowering plants went too. The situation has now markedly improved and hedges are being replanted, but the position of some of Britain's bumblebees is still precarious.
All our 22 species of bumblebee are social insects, but six of them are parasites, rather like the homeless bees. The common buff-tailed bumblebee begins its life cycle in the early spring when the young fertilised queen emerges from hibernation. She visits the first flowers of the year for nectar on sunny days, sometimes as early as February. Next, she seeks a suitable place for her colony. This is usually underground in the disused mouse or vole nest. Having hollowed out the ball of moss and grasses within, she secretes scales of wax from between the segments of her abdomen, chews them until they are pliable, then carefully moulds them into a large honeypot. Her life gets busier now, as she flies to and fro to collect nectar from tubular flowers with her long tongue. Enzymes in her crop convert the sugars in the nectar to glucose and fructose and she regurgitates the mixture into the waxen honeypot to provide her with reserves of food to tide her over periods of cold wet weather.
As she bumbles from flower to flower, her furry body gets dusted with pollen. Each hair is intricately branched with the express purpose of catching as many grains as possible. As a bee goes about its business, it periodically combs the front of its body with its front legs and the rear with the hind ones. Pollen raked from the fur in this way is then deftly transferred to an ingenious arrangement of bristles on each hind leg called the pollen basket, where it is packed tight with another implement - the pollen press. In this way the bumblebee can carry as much as 60 per cent of its already considerable body weight. On returning to her nest, she kicks off the pollen using her middle legs and uses it to build a ball of food moistened with nectar, which eventually grows to the size of her body, at which point she lays a number of eggs on its surface.
After a few weeks, during which the queen's body heat is used to help speed up their development, the grubs spin silk cocoons, then hatch as worker bees -females like the queen, but smaller and infertile. The workers now take over all domestic and foraging duties, leaving the queen to concentrate on egg-laying. The colony develops into a family of up to 300 individual bees, all of which are female, until the queen's supply of sperm dries up towards autumn. Subsequent eggs are unfertilised and develop into male bees or drones. New queens are also produced at the end of the summer: grubs destined to be queens rather than workers are fed more, so grow bigger.
By the time of the first frosts, the young queens and males have left the nest and mate with others from colonies further afield. The workers and the old queen die, as do the males once they've mated. The newly fertile queens feed on nectar and pollen to boost their fat reserves before finding a cool, dry place in which to hibernate over the winter.
Honeybees are arguably the most advanced of all social insects. In common with bumblebees, the queen is long-lived and the generations overlap. This ensures efficient rearing of young as well as vastly reducing the risks of predation to which solitary bees are prone. But here the similarity ends - honeybees are awe-inspiring in their degree of social structure and efficiency of honey production: they leave bumblebees and wasps in the cold. When Karl von Frisch discovered that they actually communicate, the scientific world was stunned (see box). Are honeybees intelligent? The answer appears to be "no", but they are certainly impressive.
Honeybees evolved in south-east Asia, where their social behaviour enabled them to co-operate so that they were able to store quantities of honey considerably in excess of their immediate needs. This allowed them to radiate far beyond their jungle origins into temperate areas, their stores of honey providing enough food and energy to cope with the worst European winters.
The honeybee's life cycle couldn't be more different from that of the bumblebee. As we've seen, the bumblebee queen awakes from hibernation to weeks of drudgery, until her duties can be taken on by the workers. The honeybee queen lives her entire life at an average temperature approaching that of the human body, but she cannot initiate a colony by herself. She is bigger than the workers, but she has no pollen-collecting apparatus on her legs or wax-secreting glands, and her jaws are not designed for fashioning the intricate hexagonal honeycomb cells.
Honeybee colonies are perennial - and very big. A hive can average 80,000 bees, with the queen laying 2,000 eggs a day. At some point, usually in early summer -the numbers get too big. The workers sense this, as the all-important chemical pheromone exuded by the queen loses its strength.
They then build special wax cells, in which grubs which would ordinarily become workers are fed a special diet. Their rate of growth becomes prodigious, and they soon turn into adult queens. As a colony can only support one, the bees become increasingly excited until the old queen flies from the hive with a cloud of workers, leaving the young queens to fight for supremacy in the diminished colony.
The first to crawl from its silk-capped cell makes a squeaking noise, called piping, which stimulates the others (some as yet unhatched) to do the same. In this way, the superior queen is guided to their cells and stings them in situ, or grapples to the death with her freshly emerged and therefore weaker rivals. The old queen and her escorts swarm on a conspicuous object such as a tree branch until scout bees return to signal the location of a likely nest-site, whereupon they fly en masse to their new home and the cycle begins again.
Nearly all our bees do an invaluable service by pollinating our wild flowers and orchard trees, but honeybees are particularly special. As providers of honey, wax, royal jelly and propolis (resin collected from trees), they take their place as one of the world's most useful domesticated animals.
BOOKS
The Hive: The Story of the Honeybee and Us by Bee Wilson (John Murray, Pounds 14.99)
Field Guide to the Bumblebees of Great Britain and Ireland; by Mike Edwards and Martin Jenner (Ocelli £9.99)
Bumblebees by Christopher O'Toole (Osmia £4.95)
Websites
* The British Beekeepers' Association (lists county association members, often willing to send representatives to schools): www.bbka.org.uk
* English Nature feature on bumblebeeswww.english-nature.org.uk/ news/story.asp?ID=468
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Can you dig it? - Article - TES Connect
Can you dig it?
Article | Published in TES Magazine on 2 February, 2007 | By: Ben Aldiss
Section:
Article
Young agricultural experts are thin on the ground nowadays, but all that could change, says Ben Aldiss, if farming programmes are encouraged
Can you identify the pictures on this page? If you had trouble, you are not alone - 99 per cent of pupils have not got a clue (*for answers see footnote). Yet all these plants and animals are integral to modern arable farming. So two years ago I set up a scheme aimed at 13-year-olds, called the School and Farm Wildlife Prog-ramme (SFWP), in an attempt to address the lack of knowledge of the British countryside.
With their increased emphasis on farming, the new GCSE science specifications are helping, but there is still a tendency for teachers to ignore agriculture when giving careers advice.
As Tim Papworth, a Norfolk farmer, told me: "We often get local schools sending pupils here for work experience, but unfortunately it is normally a last resort.
"Teachers do not seem to appreciate how technically demanding modern agriculture is these days. If they did, we would be sent more of their top achievers. That is what the countryside really needs."
So how does the programme differ from other excellent schemes putting pupils onto farms? First, by aiming to provide an England-wide, structured approach, geared closely to the curriculum. Secondly, the project provides an in-depth grounding in farming, wildlife and conservation before the farm visit, tailored to that farm. Once there, the pupils are then instructed, not only by the farmer, but also by experts in conservation, agriculture and wildlife.
The programme is popular with both pupils and teachers. Sara Watkins, the head of science at Alderman Peel High School in Wells-next-the-Sea, said:
"I had comments like 'A fantastic day for Year 9!' and we have also had a few pupils asking about career paths and courses."
Dr Angela Lawn, head of science at Knights Templar School in Baldock, Hertfordshire, said: "Teaching environmentally sustainable farming in the classroom can never match seeing it for real. Not only was the content and itinerary superb, but the pupils loved talking to the farmer.
"He was able to provide a personal touch to the discussion of balancing the needs of agriculture to feed the population of the future while recognising the responsibility we have towards the environment."
With the Government's push to get schools involved in more fieldwork I could see a new opportunity: A-level. Farmers and teachers involved in the pilot commented that, beneficial though the Year 9 focus was, the potential for sixth formers was even greater.
Using their local farm for ecology fieldwork has many advantages. Teachers of subjects such as biology and geography will be able to give pupils a meaningful practical experience at minimal cost throughout the year.
Interested schools will be matched to a suitable farm by David Bird, my colleague, and farm conservation advisers. Preliminary material will then be sent for the initial school visit. Pupils will tour most of the site with the farmer and also hear from a conservationist.
Our worksheets will enable teachers to carry out most of the ecological techniques in the A-level specifications. This work can be done at any time, agreed between the school and the farm owner, without the need for further intervention by the farmer.
Not only this, but it can directly benefit the farm - helping monitor bumblebees, butterflies and plants in field margins seeded with wild flowers for instance. For pupils, practical techniques used for a purpose are much more likely to make sense. For the SFWP as a whole, there are big bonuses. With numerous schools collecting similar data and uploading it to a central database via the SFWP website (still under construction), ecological trends can be monitored and schools can use the large datasets for follow-up work.
We are lucky to have backing from some prestigious organisations. The nine regional Science Learning Centres and the National Centre will be able to provide venues for teacher training days and a bid for major funding is being launched through the Royal Entomological Society.
We are optimistic that we will be able to expand from our base in East Anglia. So, if you are interested in being considered for the first year of the A-level SFWP, get in touch
Ben Aldiss teaches biology part-time at Thorpe House School in Norfolk. He can be contacted at The Farmers Conservation Group: www.tfcg.co.uk*1.
wheat, 2. skylark, 3. hawthorn in flower, 4. male brimstone butterfly and 5. sugarbeet.
References
GCSE
OCR's 21st century science. It includes the additional applied science single award, with an agriculture and food option.
Half of the marks for this award are gained through the work-related portfolio, part of which involves the students creating a work-related report.
Websites
Science Learning Centres:
www.sciencelearningcentres.org.uk.
FACE (Farming and Countryside Education): www.face-online.org.uk.
Growing Schools:
www.teachernet.gov.uk/growingschools.
>Federation of City Farms and Community Gardens: www.farmgarden.org.uk.
Farms for Schools:
Farms for City Children:
www.farmsforcitychildren.co.uk.
Countryside Foundation for Education:
org.uk.
The Country Trust:
Real World Learning Campaign:
www.field-studies-council.org.
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UAE judicial official condemns domestic violence
DUBAI, United Arab Emirates -- A senior Emirati judicial official stressed Wednesday that the UAE does not condone domestic abuse even though the country's highest court ruled that a man can physically "discipline" his wife and young children provided he leaves no marks.
The official's statement was strong without contradicting the court - highlighting tensions in this Gulf state between interpretations of traditional Islamic law and the country's desire to forge a modern society that is home to far more foreigners than locals.
"Our courts adhere to (a) strict policy not to tolerate any degree of family violence, whether verbal or physical," Humaid al-Muhairi, director of the Justice Ministry's judicial inspection department, said in a statement carried by state news agency WAM.
Muhairi's comments follow a report this week that the Federal Supreme Court found a man guilty of beating his wife and daughter while noting that Islamic codes allow for "discipline" if it leaves no marks.
The ruling found that the man had exceeded the "right to discipline" his family members because his wife suffered lip and teeth injuries, the state-owned daily The National reported this week.
The court also ruled that his 23-year-old daughter, who suffered bruises on her hand and knee, was too old to be disciplined by her father.
Under some interpretations of Shariah, hitting or beating is an acceptable form of domestic discipline.
The decision upheld a lower court ruling that found the man guilty of abuse and fined him 500 dirhams ($136), the paper said.
"If the husband abuses this right to discipline, he cannot be exempted from punishment," Chief Justice Falah al-Hajeri wrote in his ruling.
In Wednesday's statement, al-Muhairi defended the ruling, saying the man "was convicted of an excessive degree of chastisement of his wife" and that he had no right under Islamic Shariah law to beat his adult daughter.
He said the ruling was in line with previous judgments and that there is no evidence of widespread domestic violence in the Emirates.
"The issue remains one of concern to (the) government and the full force of the law will continue to be brought against those who may exercise chastisement of any kind, verbal or otherwise, beyond acceptable bounds," he said.
The UAE legal system, like that in other Gulf states, combines aspects of traditional Shariah law with secular civil codes. The influence of Shariah tends to be strongest in family law relating to marriage, divorce and sexual relations.
A leading human rights watchdog condemned the high court's decision, saying it upholds a discriminatory law that violates women's and children's rights to liberty, security and equality.
"This ruling ... is evidence that the authorities consider violence against women and children to be completely acceptable," Nadya Khalife of the New York-based Human Rights Watch said in a statement Wednesday.
"Domestic violence should never be tolerated under any circumstances. These provisions are blatantly demeaning to women and pose serious risks to their well-being," she said.
Emirati society has undergone dramatic changes in recent years as hundreds of thousands of foreign residents have poured in, challenging long-held values while raising the country's international profile.
The UAE is playing an increasing role in business and international relations. Its rulers are eager to safeguard the country's Islamic traditions as the country rapidly modernizes and builds cutting-edge skyscrapers and lavish, cosmopolitan hotels.
Roughly four out of every five people living in the country are temporary foreign residents.
Top 10 Firefox Extensions to Improve your Productivity - Stepcase Lifehack
Firefox is the browser of dreams for many people (myself included). One of the great perks of Firefox is that there are tons of extensions that enhance the functionality of the browser. With over 1500 extensions in existence, there are many that can be used to improve your productivity. The following is my take on the top 10 extensions that will keep you focused, reduce distractions, streamline your daily work flow, and improve your productivity.
Customize Google is a very robust extension that lets you customize many features of the services provided by Google. Customize Google lets you block advertisements on pretty much any Google page (including Gmail). It remaps Google Images search results to point directly at the images (no longer will you need to click through the originating site). Customize Google lets you add links from other search engines directly into your search results. It can also block Google click tracking and allows you to connect to Google Calendar and Gmail securely (https). Give it a try, you won’t be sorry.
2. Gspace
Gspace is a content management extension that lets you turn your Gmail account into an online mass storage device. Gspace integrates nicely into your browser and lets you drag and drop files into Gmail for backup or storage purposes without interrupting your work flow. If you use Gspace, I recommend adding a tag in Gmail to your files so they can be filtered and accessed quickly. The following is the description of Gspace from its homepage: “Gspace turns the 2GB of your Gmail account into free online storage. With Gspace you can manage unlimited Gmail accounts to store all type of files within its simple, user friendly interface. Listen to your favorite stored music directly from your Gspace, view your collections of pictures and manage your Gdrive files as well. Download Gspace now and transfer files between your computer and Gspace at anytime, from everywhere!”
3. Flashgot/DownThemAll
The default download manager built into Firefox is very handy; however, there are many occasions that you’ll find that you need more flexibility with your downloads. This is where Flashgot or DownThemAll comes in handy. The features of Flashgot and DownThemAll have their differences; however, they generally provide finer-grained control of your downloads. My personal preference is Flashgot. I recommend trying at least one of them.4. Greasemonkey Stylish Ad blocking per Gozer
Greasemonkey is an extension that lets you add scripts that alter the web pages you visit. Using Greasemonkey and Stylish and Ad blocking per Gozer together will block pretty much every advertisement from any Web site you visit.5. Flashblock
The Flashblock extension by default blocks flash from playing when a Web page is first opened. Most (distracting) advertisements are written using flash. Flashblock is particularly useful because it replaces the flash from a Web site with a “play” button so you can watch the flash if it something useful (like a video at Youtube) and leave it blocked if it is an advertisement.
Download Statusbar manages your downloads in the status bar instead of the Firefox Download Manager. I find that the download manager that comes with Firefox to be very intrusive. Download manager tucks your download progress bars into the generally unused status bar of Firefox. This lets you download care-free without the Firefox Download Manager popping up and interrupting you.
7. URL Fixer
URL fixer will replace the common typos you enter when typing a Web site into the URL bar (i.e., http://www.lifehack.rog, htp://lifehack.org). The auto correct feature of URL fixer is very helpful. “[URL Fixer] will correct common misspellings of .com, .net, .org, .edu, .gov, and .mil, as well as the protocol (http:, https:). It will also correct errors in country code TLDS such as .com.XX, .net.XX, and .org.XX.”8. Tab Mix Plus
Many of the features of Tab Mix Plus were incorporated into the release of Firefox 2. However, Tab Mix Plus allows you to add finer-grained control of your tabs. The following is a description of Tab Mix Plus: “Tab Mix Plus enhances Firefox’s tab browsing capabilities. It includes such features as duplicating tabs, controlling tab focus, tab clicking options, undo closed tabs and windows, plus much more. It also includes a full-featured session manager with crash recovery that can save and restore combinations of opened tabs and windows.”9. Scrapbook
Scrapbook is extremely useful for researchers and students. Scrapbook saves blurbs from Web pages to your hard drive along with the URL of the originating Web site. It allows you to organize and categorize your blurbs in a format similar to your bookmarks so that when it comes to creating a bibliography or works cited, you won’t waste any time.10. IE Tab
I find myself using this extension less and less as more Web developers code their Web sites following standards. However, occasionally you will find it necessary to open a Web site using Internet Explorer in order for it to render correctly. Rather than taking the time to launch a separate browser, just choose “View Page in IE tab” and an Internet Explorer tab opens in Firefox. This is very useful if you like to have multiple Gmail accounts open and active on one computer.
That’s my take on the extensions that will improve your productivity. Like I previously mentioned, there are tons of Firefox extensions. What extension didn’t I mention that you can’t live without? Please tell us about your favorite productivity-enhancing Firefox extension in the comments.
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