A new study published in the online journal PLOS One, shows even more compelling evidence of the harm caused by the use of neonicotinoids. Very low exposure, only two parts per billion, showed to have an impact on the genes of honey bee larvae.
The genes involved in breaking down toxins are particularly affected by exposure to neonicotinoids most probably to manage exposure to the pesticide. In experiments conducted on the most widely studied insect, the common fruit fly, similar genetic changes were observed along with a significant decrease in the ability of a larva surviving to adulthood.
The lead author of the study, Dr Reinhard Stöger, Associate Professor in Epigenetics in the University’s School of Biosciences tells Science Daily, “Although larvae can still grow and develop in the presence of imidacloprid, the stability of the developmental process appears to be compromised. Should the bees be exposed to additional stresses such as pests, disease and bad weather then it is likely to increase the rate of development failure.”
New findings show that neonicotinoids persist and accumulate in the soil longer than originally findings have shown. Being systemic they are also in the pollen and nectar of treated plants, which provides for their unintended spreading and harm as the concentrations are sufficient to substantially impact colony reproduction in bumblebees. Only 20% of the applied chemical remains with the seed, the other 80% is lost during sowing in the air and soil. The aerial dust alone, that results from sowing seeds, has shown to cause direct mortality in nearby flying honeybees.
The EU has placed a temporary, 2 year ban on two neonicotinoids, clothianidin and thiamethoxam, but the evidence shows that levels can remain in soil for longer than this period which hardly makes this ban effective. Also neonicotinoids will still be widely used on cereals which will continue the broad impact. The EPA in the United States recently approved Bayer’s clothianidin and thiamethoxam despite the myriad of evidence that ties neonicotinoids to colony collapse disorder.
By Matt Agorist, REALfarmacy.com
Goulson, D. (2013) An overview of the environmental risks posed by neonicotinoid insecticides, Journal of Applied Ecology on 14 June 2013. doi: 10.1111/1365-2664.12111
Kamila Derecka, Martin J. Blythe, Sunir Malla, Diane P. Genereux, Alessandro Guffanti, Paolo Pavan, Anna Moles, Charles Snart, Thomas Ryder, Catharine A. Ortori, David A. Barrett, Eugene Schuster, Reinhard Stöger. Transient Exposure to Low Levels of Insecticide Affects Metabolic Networks of Honeybee Larvae. PLoS ONE, 2013; 8 (7): e68191 DOI: 10.1371/journal.pone.0068191