Phenithionate is primarily used as an insecticide in agricultural settings to control a variety of pests that affect crops. It is effective against insects such as aphids, mites, and caterpillars, which can cause significant damage to plants. The chemical works by disrupting the nervous system of the pests, leading to their elimination.

In addition to its use in agriculture, Phenithionate is also employed in public health programs to combat disease-carrying insects like mosquitoes. This helps in reducing the spread of diseases such as malaria and dengue fever. It is often applied in areas where these insects are prevalent, providing a protective barrier that reduces their population.

Phenithionate is also utilized in veterinary medicine to treat parasitic infestations in livestock. It helps in controlling external parasites like ticks and lice, which can affect the health and productivity of animals. By keeping these pests in check, it contributes to the overall well-being and efficiency of livestock management.

Overall, Phenithionate plays a crucial role in pest management across various fields, ensuring the protection of crops, public health, and animal health.