Chemistry and biology of thiamethoxam: a second generation neonicotinoid

Thiamethoxam is the first commercial neonicotinoid insecticide from the thi anicotinyl subclass. It was discovered in the course of our, optimisation p rogram on neonicotinoids started in 1985. Novel variations of the nitroimin o-heterocycle of imidacloprid led to 4-nitroimino-1,3,5-oxadiazinanes exhib iting high insecticidal activity. Among these, thiamethoxam. (CGA 293433) w as identified as the best compound and selected for worldwide development. The compound can be synthesised in only a few steps and high yield from eas ily accessible starting materials. Thiamethoxam. acts, by binding to nicoti nic acetylcholine receptors., It exhibits exceptional systemic characterist ics and provides excellent control of a broad range of commercially importa nt pests, such as aphids, jassids,. whiteflies, thrips, rice hoppers, Color ado potato beetle, flea beetles and wireworms, as well as some lepidopteran species. In addition, a strong preventative effect on some virus transmiss ions has been demonstrated. Thiamethoxam is developed both for foliar/soil applications and as a seed treatment for use in most agricultural crops all over the world. Low use rates, flexible application methods, excellent eff icacy, long-lasting residual activity and favourable safety profile make th is new insecticide well-suited for modern integrated pest management progra mmes in many cropping systems. (C) 2001 Society of Chemical Industry.