DST-INSPIRE Fellow Ecology Research Unit, Department of Zoology & Centre for Pollination Studies
University of Calcutta
What is pollination?
Pollination is a charming natural process of transferring pollens to stigma of flowers. Most importantly, it is THE principle reason behind crop production. This priceless ecosystem service provided by all pollinators is the reason behind food being served on our plates!
Pesticides and honey bees
Honey bees are an indispensable element of agriculture and many crops are completely reliant on the pollination services provided by bees, often over a period for as short as a few days. Bee pollination is essential for the production of a variety of agricultural and horticultural crops. Honey bee is economically important for its additional role in production of marketable products like honey and wax. Honey bees also play an important role in the maintenance of biodiversity through the pollination of wild flowers and these in turn provide a source for food for many small mammal and bird species, either through herbivory or by providing prey.
In recent decades, intensive agricultural practices have led to habitat destruction and increased pesticide use, resulting in a significant reduction in both the numbers and species diversity of wild bees and other beneficial insects. In 2007, as per FAO factsheets, India alone contributed approximately 21761.19 tonnes in pesticide usage out of 106210.92 tonnes among 21 Asian nations.
Pesticides have become an indispensable yet hazardous part of modern agriculture. Honeybee is extraordinarily sensitive to a range of chemical insecticides. Foraging bees may encounter lethal insecticide levels when pollinating agricultural fields or foraging in residential settings and further mortality can occur when contaminated nectar and pollen are brought back to the hive. Pesticide exposure can have direct effects on individual bees as well as indirect effects on entire colonies. Studies in the UK and other parts of the Western world have listed pesticides and systemic insecticides as the major reasons for colony collapse disorder in managed and wild colonies (apart from Varroa mites and Nosema fungus infection).
Pesticides used in field have been found to affect bees’ ability to navigate to the hive (homing), their power of learning and memory and also their orientation. This immensely hampers a bee’s capability to forage for food, find its way back home and hence – even more crucially – bee survival! Studies have indicated that queen loss and forager bee loss as a result of indiscriminate pesticide use have also affected colony growth and numbers. Several classes of pesticides such as neonicotinoids, carbamates and organochlorines vary in their methods of affecting bee biological systems.
Growing issue with food insecurity
Apparently intensification of agriculture has been extremely profitable for the farming scenario. More and more yield can be obtained from smaller lands by increased use of pesticides, fertilizers and hardier seeds. However this has been a boomerang in the face of the farming community itself. Repeated use of chemicals has depleted the land of its natural goodness. Beneficial insects and pollinators visit less – making it harder to achieve the same yield! Drought and rain intensify the harshness of the field.
It is THE time to rethink our role in how we grow food, how much are we managing to and what the casualties of such food driven conflicts are. If managed astutely, Earth has enough to provide for all of us. However, plundering the natural resources and ill management of the food resources have led to a drastic decline in food production with increasing population. Coupled with climate change and associated droughts and flood, food security has become a burning issue in the neo world. According to the United Nations, a profound change of the global food and agriculture system is needed if we are to nourish today’s 925 million hungry and the additional 2 billion people expected by 2050.
Honey bee decline has brought about serious concerns for global food yield and has also drastically declined global economy. Millions of dollars worth of pollination service is being hampered by decline in honey bees. The value of honey bees, in agro-ecosystems, hence is undeniable.
Improvement of organic farming
Issues with global food insecurity are like a cascade reaction. With time, there has been an increase in human population. With time, our needs have magnified and diversified. With time there has been a greater depletion of resources. With time, climate change and subtle environmental changes are not only causing a loss of bio resources, like important pollinators, but are also causing further damage by means of flood and drought. Hence increasing population is causing greater demands on the existing agriculture infrastructure and there is only up to a point where one can squeeze in the most beyond which the entire agri-system may collapse.
This is where we would advise organic farming. Organic agriculture is a production system that relies on ecological processes rather than the use of synthetic inputs, such as chemical fertilizers and pesticides. Slow but steady conversion to organic farming has helped increase production for a number of farming groups. Ensuring food security is also ensuring that the environment is not damaged or depleted of its natural bounty.
Food for thought
The problems seem pretty evident but the solution is not so easy. Livelihood depends on farming for a large percentage of rural India. For these hard working people, pests are a nuisance that must be removed. Pesticide companies may seem to provide the instant solution for eradication of pests. Environmentalists may seem like the apparent pessimists. However patience, endurance and making the right farming choices can help save the environment, the pollinators, the plants, the top consumers (i.e. us) and also ensure long term yield in those lands.
Take home message
The reason for bee decline is not clearly defined. Pesticide exposure, mites and other parasitic infection, destruction of natural flowering habitats and uncontrolled destruction of nests especially in Eastern hemisphere for wild honey are the major drivers for global bee decline. Some say even radio towers and genetically modified crops are harming honey bees.
The Indian scenario is even more difficult because apart from constant habitat destruction, a multitude of pesticides are being used indiscriminately. Hence bees are not only constantly facing this immense pesticide load, they are also being thrown at the face of an array of deadly insecticides – all with the ability to severely hamper entire colonies of managed and wild honey bees.
Farmers need to be trained and made conscious of the potential threats of indiscriminate use of pesticides. Awareness, if spread across the farming community, can bring wonders for a greener earth devoid of toxic fumes and pesticides.
Reduction in the indiscriminate use of chemicals in backyard gardens and not using pesticides is a fantastic way to start protecting honey bees. Choosing organic produce at markets is another way. Plant trees, have beautiful non-toxic home gardens, keep fresh flowers in pots – let the bees come in with a breath of fresh air!
These petite creatures are of massive value to us and our environment – they hold the key to plant life and yield. Their service – free and mostly unnoticed – ensures food for every home. A sustainable environment is what we all need to aim for collectively. Only when we can harness this steady decline in bee populations, we can look forward to a productive greener earth.
Join us in this revolution. Lend your expertise or help bridge gaps at http://cpscu.in/. Let us try and make this world a safer place for our bees!
So next time when you sit down and enjoy your meal, do remember the efforts of the honey bees!
Cheers to the honey bees!
Picture courtesy http://ucanr.edu/blogs/food2025/index.cfm?tagname=citrus
Improved integrated farming to augment food and nutrition security of masses by N. G. Hegde
Atkins, E.L. (1975) Injury to honey bees by poisoning. In: The Hive and the Honey Bee. Dadant and Sons, Hamilton, 663.
Bortolotti, L., Montanari, R., Marcelino, J., Medrzycki, P., Maini, S. and Porrini, C. (2003) Effects of sub-lethal imidacloprid doses on the homing rate and foraging activity of honey bees. Bulletin of Insectology, 56(1): 63-67.
Carreck, N. and Williams, I. (1998) The economic value of bees in the UK. Bee World, 79(3): 115-23.
Chauzat, M.P., Faucon, J.P., Martel, A.C., Lachaize, J., Cougoule, N. and Aubert, M. (2006) A Survey of Pesticide Residues in Pollen Loads Collected by Honey Bees in France. Journal of Economic Entomology, 99: 253-262.
Claudianos, C., Ranson, H., Johnson, R.M., Biswas, S., Schuler, M.A., Berenbaum, M.R., Feyereisen, R. and Oakeshott, J. G. (2006) A deficit of detoxification enzymes: pesticide sensitivity and environmental response in the honeybee. Insect Molecular Biology, 15: 615–636.
Colin, M. E., Bonmartin, J.M., Moineau, I., Gaimon, C., Brun, S. and Vermandere, J.P. (2004) A Method to Quantify and Analyze the Foraging Activity of Honey Bees: Relevance to the Sublethal Effects Induced by Systemic Insecticides. Archives of Environmental Contamination and Toxicology, 47: 387-395.
Corbet, S.A., Williams, I.H. and Osborne, J.L. (1991) Bees and the pollination of crops and wild flowers in the European Community. Bee World, 72: 47-59.
Decourtye, A., Armengaud, C., Renou, M., Devillers, J. and Cluzeau, S. (2004) Imidacloprid impairs memory and brain metabolism in the honeybee (Apis mellifera L.). Pesticide Biochemistry and Physiology, 78: 83-92.
Free, J.B. (1993) Insect pollination of crops. In : Academic Press, London, U.K.
Heylen, K., Gobin, B., Arckens, L., Huybrechts, R. and Billen, J. (2010) The effects of four crop protection products on the morphology and ultrastructure of the hypopharyngeal gland of the European honeybee, Apis mellifera. Apidologie, DOI: http://dx.doi.org/10.1051/apido/2010043.
Johansen, C.A. and Kleinschmidt, M.G. (1972) Insecticide formulations and their toxicity to honeybees. Journal of Apicultural Research, 11: 59–62.
Medrzycki, P., Montanari, R., Bortolotti, L., Sabatini, A.G., Maini, S. and Porrini, C. (2003) Effects of imidacloprid administered in sub-lethal doses on honey bee behaviour: Laboratory tests. Bulletin of Insectology, 56: 59–62.
Williams, I.H. (2002) Insect Pollination and Crop Production: A European Perspective . IN: Kevan P & Imperatriz Fonseca VL (eds) – Pollinating Bees – The Conservation Link Between Agriculture and Nature – Ministry of Environment / Brasília, 59-65.
Williams, I.H. and Carreck, N.L. (1994) Land use changes and honey bee forage plants. In: Forage for bees in an agricultural landscape. International Bee Research Association, Cardiff, 7-20.
Short Bio of the author:
Priyadarshini Chakrabarti (Basu) is currently pursuing Ph.D. at the University of Calcutta (C.U.). She is a Senior Research Fellow at the Department of Zoology and Centre for Pollination Studies (CPS) at C.U. She secured First Class First from C.U. in Masters in Zoology, First Class Third in Bachelors (Honours) in Zoology (C.U.) and the prestigious DST-INSPIRE Fellowship from Government of India for pursuing Ph.D. She lectured in Zoology for two years at the graduation level in Asutosh College, C.U. She also received numerous awards such as Sudev Bhushan Ghosh Young Scientist Award and K. C. Ghosh Memorial Medal from Zoological Society, Kolkata to name a few. With an urge to transform the agricultural practices and belief in pollinator friendly techniques – she works in remote villages of Eastern Indian states of West Bengal and Odisha in close association with the farmers. As an active member of CPS, she participates in farmers’ meetings and awareness programmes held by CPS in Odisha and Tripura. Her principal focus is on the effects of pesticides on honey bees and how pollinator friendly approach can help save honey bee populations. Apart from participating and presenting at numerous conferences in India and abroad, her articles are also published in environmental magazines. She has also undertaken training in honey bee behavior at IISER, Trivandrum. More information can be found at http://cpscu.in/?page_id=49.