A Closer look neonicotinoids

摘要

A novel group of insecticides, the neonicotinoids, has become popular among growers and farmers worldwide for its high degree of effectiveness against a wide range of insect pests and its low vertebrate toxicity. Neonicotinoids used in agriculture andhorticulture are predominately xylem-systemic insecticides with high acute and residual toxicity to sucking insects, such as aphids and mealybugs; and chewing insects, including leaf-miners and several beetle species. Their mode of action is similar tonicotine, which affects the central nervous system in both mammals and non-vertebrates; but neonicotinoids block a specific pathway that is far more abundant in insects than in mammals, rendering them much safer than other insecticide classes to animalsand humans. Neonicotinoid insecticides are applied as seed treatments, soil drenches, in furrows and as foliar sprays, and are considered one of the best control options for early-season pests. Even though they have been on the market for more than 20 years, very little resistance has been reported in crop pests, unlike their predecessors which include synthetic pyrethroids, chlorinated hydrocarbons, organophosphates, and carbamates. As far as we can tell, this new generation of insecticides, the neonicotinoids, poses little threat to the environment or human consumers.