Associate Certified Entomologist (ACE) Practice Exam

Which of the following is NOT considered an organochlorine?

1. DDT

2. Lindane

3. Malathion

4. Aldrin

The correct answer is: Malathion

Malathion is not classified as an organochlorine compound. Instead, it belongs to the category of organophosphates, which are different from organochlorines in both structure and mode of action. Organochlorines, such as DDT, Lindane, and Aldrin, are characterized by their chlorine atom content and their persistence in the environment. DDT, Lindane, and Aldrin are all known for their historical use as pesticides and are associated with significant environmental persistence and bioaccumulation in wildlife. They work primarily by disrupting the nervous system of pests. In contrast, Malathion operates by inhibiting an enzyme essential for nerve function, thereby representing a different class of chemical insecticides. This distinction between organochlorines and organophosphates is crucial in understanding their varying environmental impacts and modes of action in pest management.