Abstract: Methomyl is a carbamate insecticide. As a broad spectrum insecticide, it is one of the most frequently applied pesticides in China and in the world, and was ranked as the chemicals suspected of having endocrine disrupting effects by the World Wildlife Fund International in 1997. For its large application amount, strong mobility in soil, high solubility in water, and long half life in water and soil, methomyl has been presented in many soils and surface and ground waters for a long time, producing potential risks to the aquatic ecosystem and the drinking water sources of human beings. This paper reviewed the applications of methomyl, its residue in water and soil environments and acute toxicity to organisms, its environmental hormone effect, oxidant damage effect, organ damage effect, and genetic toxicity. Accordingly, the key issues still needed to be further studied in the future were proposed, aimed to better understand the present status of methomyl pollution and its potential risks to organisms and ecosystems, and to provide useful information to take effective measures to control the harmful effect of methomyl and to protect biological resources and ecosystems.

Key words: land use, ecological risk, Karst basin, Lijiang River basin.