Studies have confirmed traces of fluvalinate concentrations in honey and wax samples obtained from colonies that were treated with two strips of Apistan. [Gatien, 2003]
Besides these In-hive chemicals, bees are also affected by the agricultural pesticides when they feed on the pollens. Though these pesticides undergo a rigorous testing phase before they are made commercially available, the risk factors for Non-target ecosystems are not always fully understood. With newer pesticides appearing on the market to replace older ones, which have become less effective due to the development of resistance by pests, the risk for non-target species is also on the rise. A case in point is the recent study in France, which has implicated the new pesticide Imidacloprid (a Neonicotinoid insecticide) as the cause for the significant loss of bee colonies. Imidacloprid is found to be a safe pesticide due to its low toxicity among mammals and hence it is used extensively for pest control in big farms. While some studies report higher levels of the pesticide in pollens and nectar of the plants, others have failed to detect any residual levels of these chemicals or their metabolites. As Kimberly stoner, a Connecticut-based entomologist says, "the pesticide is put on the seed, and the plant takes in that pesticide and moves it through the vascular system of the plant" "Bees are potentially picking them up in pollen and nectar and low levels that don't kill the bees, but that might affect their behavior and immune system" [Susan Salisbury, 2008]
A study by Laurent and Rathahao (2003) analyzed the concentrations of Imidacloprid in sunflower plants that were grown from seeds treated with the pesticide. This study was prompted by reports of unusual bee behavior by colonies that fed on these Imidacloprid treated plants. Based on radioactivity measurements, the researchers found that the plants absorbed around 10% of the pesticide treated on the seeds. Of this, 75% of the radioactivity was noticed in the cotyledons. The study also showed that the radioactivity measurements were 20 times lesser in upper leaves compared with lower leaves. This study confirmed that seed treatment affected the entire plant due to vascular translocation of the pesticide indicating the potential for bee poisoning. [Laurent, 2003]
Other studies have also reported negative effects of Imidacloprid use on the memory and brain metabolism in honeybees. Decourtye et.al (2003) showed that oral administration of Imidacloprid affected the olfactory responses of honeybees in a 'proboscis extension reflex' test. When administered 15 minutes after a PER test, it was clear that Imidacloprid compromised medium term olfactory memory. Increase in levels of cytochrome oxidase indicated pesticide-induced changes in brain metabolism and changes in neuronal transmission. [Decourtye et.al (2003)]
Gm crops and Bio pesticides
GM farming is considerably developed particularly in the United States and South American countries. GM crops that have built in pesticides are generally thought to be environmentally friendly, as they do not require the usual treatment with toxic pesticides. However, these genetically modified crops that are programmed to selectively express genes that produce peptides that have insecticidal properties could be toxic to honeybees. Since commercial production of GM crops is already a practice in many farms, studies that assess the impact of the ingestion of pollens or nectar of such genetically modified crops on bee health acquire significance. Malone et.al (2000) is one such study. This research studied the bees foraging on transgenic crops and the effects on their gut physiology, olfactory memory and longevity. In particular the effect of 'protease inhibitors', 'chitinase,' 'glucanase' and 'biotin-binding protein genes' were observed. The study concluded on a cautionary note that the biological effect of the transgenic material would depend on their type and the quantity of ingestion. Besides GM, plants are a perennial source of insecticidal proteins (expressed in their pollens and leaves) the effects of which have to be studied further. However, the results from this study showed that transgenic insecticidal proteins were much less toxic to bees and other mammals when compared to the standard industrial chemicals. [Malone A, 2001] At the moment though, there is not much research evidence to implicate GM crops induced toxicity in the chronic collapse disorder of bees.
The Changing Bee culture
The beekeeping culture has changed dramatically over the last few decades. Colonies are transported from one place to other; queen bees are artificially bred and developed. Bees are fed with huge quantities of corn syrup with little concern about their digestive metabolism. In the opinion of some researchers, commercial lease of bee colonies for pollination...
Bee Colony Collapse John Smith, Environmental Defense Fund Dear Mr. Smith, thank you for your thoughtful letter concerning the issues surrounding the "colony collapse" of honeybees. We are critically aware of this problem and we are searching for answers along with scientists, environmental experts, and others who recognize the vital role that honeybees play in the production of food in the United States and in the world. However, at this time, we are
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