Neonicotinoids pesticides

Recently, the word "neonicotinoids" as a group of insecticides appear frequently in various news reports because the concerns of their association with the increasing mortality rate of honeybees. Because of the potential impact on the pollinators including honeybees, neonicotinoids are at a stage of "near ban". High priority for conducting further risk assessment on neonicotinoids is given by chemical regulations agencies.

Let's have a closer look at neonicotinoids

As indicated by the name, neonicotinoids are related to nicotine.

nicotine

Neonicotinoids is a group of pesticides most widely used in the world. The group includes

acetamiprid

clothianidin

imidacloprid

nitenpyram

nithiazine

thiacloprid 

thiamethoxam. 

Neonicotinoids act on the central nervous system of insects. Neonicotinoids can bind to some receptors in the nervous system and prevent impulses transmitting between nerves. This biochemical action mechanism would make insecticides exposed to neonicotinoids unable to move and eventually die.

Neonicotinoids have high water solubility and break down slowly in soil. They are often applied to soil and be taken up by plants and provide protection from insects as the plant grows.

When developed, neonicotinoids were claimed to have low-toxicity to many beneficial insects, including bees. However,  toxic effects to bees and other beneficial insects have been realized recently. Bees and other pollinators expose to neonicotinoids through nectar and pollen where neonicotinoids are used in agriculture for pest control. Although the exposed levels are sub-lethal , they may impact some bees’ ability to navigate to flowers and nectar.

Despite some controlled studies, more information is still needed to link neonicotinoids to the bee colony collapse disorder and increased mortality rate of honeybees. However, to keep potential risk to bees and other beneficials low, Corn farmers in Ontario and Quebec are requested to use dust deflectors on their seed planters, and that the seed companies use a seed lubricant to minimize the dust that is emitted during planting.

References and more information:

http://www.theglobeandmail.com/report-on-business/new-usda-survey-reveals-alarming-increase-in-honeybee-mortality-rate/article24420306/
http://www.wsj.com/articles/over-40-of-honeybee-colonies-died-in-year-usda-says-1431531544
http://www.huffingtonpost.com/jon-entine/neonics-not-key-driver-of_b_6928578.html
http://www.bulletinofinsectology.org/pdfarticles/vol67-2014-125-130lu.pdf