Deltamethrin is a pyrethroid ester insecticide. Deltamethrin plays key role in controlling malaria vectors, and is used in the manufacture of long-lasting insecticidal mosquito nets. It is used as one of a battery of pyrethroid insecticides in control of malarial vectors, particularly Anopheles gambiae, and whilst being the most employed pyrethroid insecticide, can be used in conjunction with, or as an alternative to, permethrin, cypermethrin and other organophosphate-based insecticides, such as malathion and fenthion. Resistance to deltamethrin (and its counterparts) is now extremely widespread and threatens the success of worldwide vector control programmes. Deltamethrin products are among the most popular and widely used insecticides in the world[citation needed] and have become very popular with pest control operators and individuals in the United States. This material is a member of one of the safest classes of pesticides: synthetic pyrethroids. This pesticide is highly toxic to aquatic life, particularly fish, and therefore must be used with extreme caution around water. It is neurotoxic to humans and has been found in human breast milk. Since deltamethrin is a neurotoxin, it attacks the nervous system. Skin contact can lead to tingling or reddening of the skin local to the application. If taken in through the eyes or mouth, a common symptom is facial paraesthesia, which can feel like many different abnormal sensations, including burning, partial numbness, 'pins and needles', skin crawling, etc. There are no reports indicating that chronic intoxication from pyrethroid insecticides causes motor neuron damage or motor neuron disease. However, in 2011, a case report was published demonstrating pathologically proven motor neuron death in a Japanese woman after acute massive ingestion of pesticides containing pyrethroids and organochlorine. There are many uses for deltamethrin, ranging from agricultural uses to home pest control. Deltamethrin has been instrumental in preventing the spread of diseases carried by tick-infested prairie dogs, rodents and other burrowing animals[citation needed]. It is helpful in eliminating and preventing a wide variety of household pests, especially spiders, fleas, ticks, carpenter ants, carpenter bees, cockroaches and bedbugs. Deltamethrin is also one of the primary ingredients in ant chalk.