Cyhalothrin is an organic compound that is used as a pesticide. It is a pyrethroid, a class of man-made insecticides that mimic the structure and insecticidal properties of the naturally-occurring insecticide pyrethrum which comes from the flowers of chrysanthemums. Synthetic pyrethroids, like lambda-cyhalothrin, are often preferred as an active ingredient in insecticides because they remain effective for longer periods of time. It is a colorless solid, although samples can appear beige, with a mild odor. It has a low water solubility and is nonvolatile. It is used to control insects in cotton crops. Pyrethroids, including lambda-cyhalothrin, disrupt the functioning of the nervous system in an organism. By disrupting the nervous system of insects, lambdacyhalothrin may cause paralysis or death. Temperature influences its effectiveness.