Acaricides are substances that kill mites and ticks. This includes substances as diverse as targeted antibiotics, certain insecticides and diatomaceous earth. Acaricides are widely used in agriculture to protect crops from mites. They are also found in pet products that protect animals against ticks.
Mites and ticks are members of Acarina, a subclass of arachnids. An acaricide can be subdivided depending on its end use. A miticide is an acaricide that kills mites, and an ixodicide is an acaricide that kills ticks. They are available in different formulations depending on whether they are to be used on humans, animals or plants.
Acaricides work by interfering with the nerves, muscles, respiration or growth of mites and ticks. Most acaricide formulations are not interchangeable. Products made for lawns should not be used on pets, and products made for pets should not be used on people. Some acaricides might be toxic to fish and other wildlife, and one must take care to use the product only as intended and to follow the manufacturer’s directions for application.
Spider mites can cause problems in gardens and can be effectively treated with commercial miticides. Mites are capable of causing devastation to agricultural crops. Miticides generally are targeted for use on plants, because mites rarely live on people. Scabies and chiggers are mites that are known to bite people, and there are topical acaricide formulations made to kill them while they are on the skin. Areas known to harbor large populations of chiggers can be treated with agricultural acaricides.
Ticks cause more health problems than mites do. Although mites are a nuisance, ticks can carry fatal diseases such as Lyme disease, Rocky Mountain spotted fever and tick-borne encephalitis. Woodlands that have tick infestations can be moderately treated with area-wide applications of ixodicides. Animals are at the highest risk for tick bites. Many commercial acaricide preparations need only a monthly application on pets to control and kill ticks.
Two of the least-toxic acaricides are diatomaceous earth and pyrethrin-based compounds. Diatomaceous earth is the pulverized shells of tiny fossils. The shells have razor-sharp edges that cut the exoskeleton of mites and ticks, causing them to dehydrate and die. Although it is not a fast method, diatomaceous earth is effective and safe to use around people and can be applied directly on pets. Pyrethrins are natural chemicals derived from chrysanthemums that, although they are less toxic than other insecticides, require direct contact with mites and ticks to be effective.