A bee's life

A member of the Augochlorine bee family pollinates a tomato flower. Credit: Courtesy of USDA Natural Resources Conservation Service On an organic farm in central New Jersey, the plants are vibrating with bees. With a swift twist of her insect net, Rachael Winfree captures a wild bee s

By | October 1, 2008

<figcaption>A member of the Augochlorine bee family pollinates a tomato
                flower. Credit: Courtesy of USDA Natural Resources Conservation Service</figcaption>
A member of the Augochlorine bee family pollinates a tomato flower. Credit: Courtesy of USDA Natural Resources Conservation Service

On an organic farm in central New Jersey, the plants are vibrating with bees. With a swift twist of her insect net, Rachael Winfree captures a wild bee smaller than an adult human's little fingernail, without disturbing so much as a petal of the plant it was pollinating. She is standing over a patch of weeds between rows of upstanding garlic and sprawling watermelon vines, in a region that's part of the Stony Brook Watershed. It is high summer, hot and sunny. Perfect weather for bees.

Unlike commercial bees, which are raised by humans, wild bees create their own living arrangements in the ground, or hollow trees, or construct a nest similar to that of a wasp. They range from the large bumble, Bombus impatiens, down to members of the Helictus genus, the largest family of small bees living and working in New Jersey and Pennsylvania. Winfree, an entomologist at Rutgers University, is evaluating "ecosystem services" we get from wild bees - in another word, pollination.

In one study, which measured wild bee visitation to four summer vegetable crops on 29 farms in New Jersey and Pennsylvania over a 2-year period, she recorded 7,400 bee visits and identified 54 species of wild bee. Wild bees were the dominant pollinators for three of the four crops studied: watermelon, tomatoes, and peppers, with cantaloupe being the one more attractive to honeybees.

Scientists in the United Kingdom have found that eight of its bumble bee populations have increasingly restricted ranges and three have vanished altogether. But US researchers have not conducted long term monitoring of wild bee populations, Winfree notes. "There are questions we can't answer."

There is reason for concern: When farm fields are expanded and hedgerows eliminated, much of the habitat for wild bees is lost. Winfree shows me two aerial photographs in scale; one of California's Central Valley and one of an area in southeastern Pennsylvania, which includes a farm where Winfree has done some of her research. The difference is striking. The California fields are "clean," farmed right up to the road or irrigation ditches. Loss of habitat is a problem for California growers, particularly in the almond groves. The Pennsylvania photograph shows small farms with fields and woodlots, surrounded by suburban housing, golf courses and streams with wooded banks - full of habitat for the bees, as well as supplies of weeds and wildflowers, good sources of pollen when vegetable and fruit crops are not in bloom.

And habitat loss isn't the only concern. Southern New Jersey is a major cranberry region and farmers usually bring in hives of commercial honey bees to pollinate the plants. Since cranberry flowers are difficult to pollinate, the growers first spray the surrounding area with herbicide so the honey bees will concentrate on the cranberry flowers and not the wildflowers and weeds. The result is that, over the long term, food for wild bees (wildflowers and weeds) is eliminated.

In one experiment, Winfree and one of her graduate students found a farm that had not yet imported the commercial honeybees or sprayed herbicide, and clipped some cranberry flowers. Back in her laboratory, under the microscope, she found that all of the flowers had been pollinated, meaning that all would have borne fruit without needing to import honey bees. Concluding the story with a grin, she says, "Great for a grant application."

Winfree is also currently working with Martin Wikelski, the newly appointed director of the Max Planck Institute of Ornithology at Seewiesen, Germany. Their plan is to develop a lightweight transmitter that can be carried by bumblebees, so the researchers can track their movements using satellite technology. "This will open up a whole new field of research," she says.


Avatar of: Ram Sihag

Ram Sihag

Posts: 12

October 15, 2008

In the scientific conferences on bees or environment where I am invited, I am often asked to deliver a talk on "Why to conserve pollinators??, In the beginning of my lecture I ask a question from the audience,? What is the most beautiful gift of nature?" Varied replies are received. But, what I clarify is different. I rank the beauty winners in the following sequence. (1) The second runner-up is the human female/male, as it has very beautiful body that fascinates human-males/females a lot, as the case be. (2) The first runner-up jointly are three Bs i.e. birds, butterflies and bees. These are magnificent and very important pollinators. These radiant coloured creatures greatly fascinate human beings due to their beauty. (3) But, most beautiful gift of nature, as I choose, is the angiosperms, the flower bearing plants. The latter provide food, fiber and shelter to human beings. In fact, these are considered to be the back bone of evolution of human civilization on earth. But, most important is the fact that the vividly coloured flowers provide picturesque beauty to the earth ecosystem. Can there be earth without angiosperms? Yes, it is possible if there are no pollinators. There fore, for the conservation of angiosperms, conservation of pollinators is most important 10. \nIn India, we have been working on the conservation of wild bees since last many years. We published our results in some books and journals 1-10. Our work was greatly appreciated by several leading government and academic bodies. United States Department of Agriculture recognized us with a Group Award( 1993): Indian Council of Agricultural Research, New Delhi awarded us the prestigious ?Rafi Ahmad Kidwai Memorial Prize (1980-82); Environment Society of India, Chandigadh awarded ?Life Time Achievement Award for Conservation of Biodiversity and Environment(2007); Educational ,Cultural and Social Welfare Society of India, Hisar awarded ? E.P.Odum Memorial Award for Conservation of Environment (2008).\n In my opinion, wild bees have greater significance in ecosystem than their domesticated counter parts. Most of the wild bees are specialist pollinators. In such cases, the generalist pollinators, like honeybees, often fail to pollinate the flowers of these plants or these are poor pollinators of such plants. I under stand that Rachael Winfree will ultimately direct her efforts in the direction of conservation of wild bees. This will be a very timely venture and the one that should attract the attention of all entomologists. The entomologists world over generally look after the plant protection part and they often forget about the safety of bees, especially the wild bees. Likewise, excessive ploughing/irrigation and removal of nesting places of wild bees have threatened their survival.The soil scientists and agronomists should also work towards the conservation of bee habitats. This will help conservation of wild bees which are not only beautiful but also an integral part of our ecosystem.\n\nReferences\n\n1. Sihag, R.C. 1983.Life cycle pattern, seasonal mortality, problem of parasitization and sex ratio pattern in alfalfa pollinating megachilid bees. Zeit.angew.Ent. 96(4), 368-79.\n2. Sihag, R.C.1990b. Behaviour and ecology of the sub-tropical carpenter bee. Xylocopa fenestrata F.2 Host plant association. Indian Bee J. 52(1-4), 38-40.\n3. Sihag, R.C., 1991. Methods of domiciling and bee keeping with alfalfa pollinating sub-tropical megachilid bees. Korean J.Apic. 6(2), 81-88.\n\n4. Sihag, R.C.1992 . Utilization of waste stems of sarcandas and castor as nesting tunnels for culturing/keeping wild bee pollinators of some crops. Bioresource Technology, vol.42, no.2, pp.159-162, \n5. Sihag,R.C.1993a. Management of some sub-tropical megachilid bees for pollination of alfalfa (Medicago sativa L.) and pigeonpea (Cajanus cajan(L) Millsp). In: Pollination in Tropics, by G.K.Veeresh, R.Uma Shankar and K.Ganeshaiah (Eds.), Pub. IUSSI- Indian Chapter, Bangalore, pp: 229-232. \n6. Sihag, R.C. 1993b.Behaviour and ecology of the sub-tropical carpenter bee, Xylocopa fenestrata F.7. Nesting preferences and response to nest translocation. J. Apic Res., 32, 102-108\n7. Sihag, R.C.1995. Management of sub-tropical solitary bees for pollination. In: Pollination of Cultivated Plants in Tropics, by D.W.Roubik(Ed.), F.A.O.Rome, pp: 157-160.\n8. Sihag,R.C.1997..Utilization of non-Apis bees as pollinators of crops. In : Pollination Biology : Basic and Applied Principles, by R.C.Sihag (Ed.), Rajendra Scientific Publishers, Hisar, PP: 152-169.\n9. Sihag, R.C.1997-98. Wild Apis and non-Apis bees: their behaviour, management and utilization. In : Perspectives in Indian Apiculture, by R.C.Mishra, (Ed.)Agro-Botanic, Bikaner, pp : 248-264. \n10. Sihag, R.C. and Singh, M. 1999.Why should the pollinators be conserved? Current Sci. 77(5), 626-627.\n

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