Organophosphorus pesticides are prohibited in many countries, but people still use them, especially in developing countries.

    We have done an investigation on field near our university. Similar to the situations of other field, they always suffered from injurious insects. We consulted farmers there about the usage of organophosphorus pesticides. Some of they told us this serval pesticides were significantly effective and sometimes used. At the same time, we search for lots of literatures. Then, we decided to focus on organophosphorus pesticides.