1. History

2. Mechanisms of action

3. Toxicity

4. Regulation
    United States   Neonicotinoids banned by the European Union   Other countries 

5. References

Thiamethoxam is a systemic insecticide in the class of neonicotinoids. It has a broad spectrum of activity against many types of insects. Thiamethoxam affects bumblebees negatively according to independent European scientific studies from 2014^[3] and 2016^[4].

History

Thiamethoxam was developed by Syngenta{{when|date=September 2014}}; a patent dispute arose with Bayer which already had patents covering other neonicotinoids including imidacloprid. In 2002 the dispute was settled, with Syngenta paying Bayer $120 million in exchange for worldwide rights to thiamethoxam.^[5][6]{{primary source inline|date=September 2014}}

Mechanisms of action

Thiamethoxam is a broad-spectrum, systemic insecticide, which means it is absorbed quickly by plants and transported to all of its parts, including pollen, where it acts to deter insect feeding.{{citation needed|date=September 2014}} An insect can absorb it in its stomach after feeding, or through direct contact, including through its tracheal system. The compound gets in the way of information transfer between nerve cells by interfering with nicotinic acetylcholine receptors in the central nervous system, and eventually paralyzes the muscles of the insects.^[7]{{rp|17}}

Syngenta asserts that thiamethoxam improves plant vigor by triggering physiological reactions within the plant, which induce the expression of specific "functional proteins" involved in various stress defense mechanisms of the plant allowing it to better cope under tough growing conditions, such as "drought and heat stress leading to protein degradation, low pH, high soil salinity, free radicals from UV radiation, toxic levels of aluminum, wounding from pests, wind, hail, etc, virus attack".^[8]{{rp|16}}

Toxicity

The selective toxicity of neonicotinoids like thiamethoxam for insects versus mammals is due to the higher sensitivity of insects' acetylcholine receptors.^[9]

The Food and Agriculture Organization (FAO) of the U.N. assessed thiamethoxam as "moderately hazardous to humans (WHO class III)", because it is harmful if swallowed. It found it to be no skin or eye irritant, and not mutagenic in any in vitro and in vivo toxicology tests.^[7]{{rp|20}}

FAO described thiamethoxam as non-toxic to fish, daphnia and algae, mildly toxic for birds, highly toxic to midges and acutely toxic for bees.^[7]{{rp|20}} The Globally Harmonized System of Classification and Labelling of Chemicals (GHS) classification is: "Harmful if swallowed. Very toxic to aquatic life with long lasting effects".^[7]{{rp|20}}

Regulation

United States

Thiamethoxam is approved for use in the US as an antimicrobial pesticide wood preservative and as a pesticide; it was first approved in 1999.^[11]{{rp|4 & 14}} As of 2014, it is approved for use in a wide range of crops.^[12]

On September 5, 2014 Syngenta petitioned the EPA to increase the legal tolerance for thiamethoxam residue in numerous crops.^[13] It wants to use thiamethoxam as a leaf spray, rather than just a seed treatment, to treat late to midseason insect pests.^[14]

Neonicotinoids banned by the European Union

In 2012, several peer reviewed independent studies were published showing that several neonicotinoids had previously undetected routes of exposure affecting bees including through dust, pollen, and nectar; that sub-nanogram toxicity resulted in failure to return to the hive without immediate lethality, the primary symptom of colony collapse disorder; and showing environmental persistence in agricultural irrigation channels and soil. However, not all earlier studies carried out before 2014 have found significant effects.^[15] These reports prompted a formal peer review by the European Food Safety Authority, which stated in January 2013 that neonicotinoids pose an unacceptably high risk to bees, and that the industry-sponsored science upon which regulatory agencies' claims of safety have relied on may be flawed and contain several data gaps not previously considered.^[16] In April 2013, the European Union voted for a two-year restriction on neonicotinoid insecticides. The ban restricts the use of imidacloprid, clothianidin, and thiamethoxam on crops that attract bees.^[17]

In February 2018, the European Food Safety Authority published a new report indicating that neonicotinoids pose a serious danger to both honey bees and wild bees.^[18] In April 2018, the member states of the European Union decided to ban the three main neonicotinoids (clothianidin, imidacloprid and thiamethoxam) for all outdoor uses.^[19]

Other countries

Thiamethoxam is approved for a wide range of agricultural, viticultural(vineyard), and horticultural uses.^[7]{{rp|17}}

References

• Vehicle registration plates of the United States for 2003
• Vehicle registration plates of the United States for 2004
• Vehicle registration plates of the United States for 2005
• Vehicle registration plates of the United States for 2006
• Vehicle registration plates of the United States for 2007
• Vehicle registration plates of the United States for 2008
• Vehicle registration plates of the United States for 2009
• Vehicle registration plates of the United States for 2010
• Vehicle registration plates of the United States for 2011
• Vehicle registration plates of the United States for 2012
• Vehicle registration plates of the United States for 2013
• Vehicle registration plates of the United States for 2014
• Vehicle registration plates of the United States for 2015
• Vehicle registration plates of the United States for 2016
• Vehicle registration plates of the United States for 2017
• Vehicle registration plates of the United States for 2018
• Vehicle registration plates of the United States for 2019
• Vehicle registration plates of the U.S. Virgin Islands
• Vehicle registration plates of the Virgin Islands
• Vehicle registration plates of the Virgin Islands (disambiguation)
• Vehicle registration plates of Togo
• Vehicle registration plates of Tonga
• Vehicle registration plates of Tuvalu
• Vehicle registration plates of Uganda
• Vehicle registration plates of Vanuatu