By Archisman Bhattacharjee (M. Sc. (Zoology) Maulana Azad College, Kolkata, West Bengal, India)
“A bee is an exquisite chemist” – Royal beekeeper to Charles II
Honeybees being a social organism perform a pivotal role in ecosystem. The preeminent role performed by bees is that of bringing about pollination in plants, this relation and interdependence of plants and bees had lead catastrophe in bee world. “Swallows have disappeared; bees are dying out because of pesticides that should have been banned long ago. It’s a scandal”- Brigitte Bardot. It is no longer a mystery, we know what’s killing the bees; they are poisoned by pesticides especially by neonicotinoid insecticides. Contact pesticides are usually sprayed on plants and kill bees when they crawl over sprayed surfaces of plants or other areas around it; they die immediately or may contaminate the entire colony. Systemic pesticides are usually incorporated into the soil or onto seeds and move up into plant parts.
Types Of Toxicity And Symptoms
Acute toxicity of pesticides on bees may be either cotactor ingestion is quantified by LD50.
- Wing paralysis
- Uncoordinated movement
Field exposure of bees to pesticides such as neonicotinoids has sub lethal effects.
- Thermoregulatory disorders
- Reduced foraging
- Decreased flight
Neonicotinoids are especially confirmed to cause Colony Collapse Disorder (CCD) which binds nicotinic acetylcholine receptors which are abundant in bee brain. Over accumulation leads to paralysis and death. In CCD Syndrome there is sudden loss of adult bees from the hive.
Results-incidents of bee death Deaths (%) due to pesticides in some districts’ of Mahavelli, Sri Lanka:
Source: WHO, derived from Perera and Gunatilleke 1990.
Managed honeybee colony losses (%) in US
Discussions On Measure Of Protection
Environmental Protection Agency (EPA) is an independent organization of the United States federal government a sincere step for environmental protection. EPA has laid down certain ground rules and instructions for use of pesticides. EPA is proposing to prohibit the application of certain pesticides and herbicides known toxic to bees during pollination periods, which reduces exposure of bees to pesticides. Ban on certain highly toxic pesticides:
- Aldrin banned by U.S. EPA in 1974.
- Dieldrin banned by U.S. EPA in 1974.
- Heptachlor, Lindane, BHC banned in California later by U.S. EPA in 2006. General measures include application of pesticides at evening or night i.e. avoiding their foraging time, restricted use of pesticides in private gardens.
Impact Of Bees On Human Life
“If bees disappear from the surface of earth man would have not more than four years of life left”
– Albert Einstein
Bees being an essential pollinator plays pivotal role in bringing about pollination in plants. One–third of our food supply relies upon bees’ pollination service which is essential for the reproduction in plants. The honey bee being the major pollinator of many of our food crops such as almond, apples, avocados, blueberries, cantaloupes, cherries, cranberries, sunflowers, watermelon and many other crops. The pollination service provided by insects mainly bees was 153 billion Euros in 2005 for main crops that feed the world. The amounted to 9.5% of the total value of the world agricultural food. So, if bees disappear and we do not find replacements for pesticide problems, then the food we take for granted will decrease in supply and will be inflation in price. Just as much as bees have a role in ensuring the survival of humanity, we should also have roles in their survival; or else “If we die we’re taking you with us” is a possible nemesis.
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