mite

mite¹

/muyt/, n.

any of numerous small to microscopic arachnids of the subclass Acari, including species that are parasitic on animals and plants or that feed on decaying matter and stored foods. Also called acarid.

[bef. 1000; ME myte, OE mite; c. MD mite, OHG miza midge]

mite²

/muyt/, n.

1. a contribution that is small but is all that a person can afford.

2. a very small sum of money.

3. a coin of very small value.

4. a very small object.

5. a very small creature.

adv.

6. to a small extent; somewhat (often prec. by a): a mite selfish.

[1300-50; ME myte < MD mite small copper coin; ult. identical with MITE¹]

* * *

Any of about 20,000 species of tiny arachnids (subclass Acari, sometimes Acarina or Acarida).

Species range from microscopic to 0.25 in. (6 mm) long. Mites live in water and soil, on plants, and as plant and animal parasites. Both parasitic and nonparasitic forms transmit plant and animal diseases. Itch mites (family Sarcoptidae), which burrow into the skin of humans and animals, cause the highly contagious disease scabies. A few species transmit tapeworms to cattle. Grain mites (family Glycyphagidae) damage stored products and irritate the skin of those who handle the products. House dust allergy is caused by species of the common genus Dermatophagoides. See also chigger.

Red velvet mite (Dinothrombium; magnified about five times)

Anthony Bannister

Natural History Photographic Agency/EB Inc.

* * *

▪ arachnid

 any of about 30,000 species of tiny arthropods, members of the mite and tick subclass Acari (class Arachnida), that inhabit a wide range of habitats, including brackish water, fresh water, hot springs, soil, plants, and (as parasites) animals, including human beings. Parasitic forms may live in the nasal passages, lungs, stomach, or deeper body tissues of animals. Some mites are carriers of human and animal diseases. Plant-feeding mites cause damage by feeding on leaf tissues or by transmitting viral diseases.

      Mites are small, often microscopic in size, with the smallest being about 0.1 mm (0.004 inch) in length and the largest being about 6 mm (0.25 inch). They usually have four pairs of legs. In general, they breathe by means of tracheae, or air tubes, but in many species, respiration takes place directly through the skin.

      Mites of the suborder Mesostigmata (order Parasitiformes) include the chicken mite, the northern fowl mite, and the rat mite, all of which attack humans. In addition, there are nasal mites of dogs and birds, lung mites of monkeys, and predatory mites, which are sometimes of benefit in controlling plant-feeding mites.

      The suborder Oribatida (oribatid, or beetle, mites) of the order Acariformes occur in soil and humus and occasionally on tree trunks and foliage. In general, they are not harmful and may play a role in the breakdown of organic matter. A few species transmit tapeworms to cattle or other ruminants.

      Mites of the suborder Astigmata (order Acariformes) include the grain and cheese mites (Acaridae), itch mites (Sarcoptidae) of humans and animals, scab mites (Psoroptidae), feather mites of birds, mites associated with insects, and many free-living forms. Grain mites (Glycyphagidae) not only damage stored products but also cause skin irritations in those who handle such products. Itch mites burrow into the layers of the skin of humans, as well as into the hides of dogs, pigs, sheep, and goats, causing injury. Scab mites are found on sheep and cattle, sometimes causing serious injury. Others are found in the air sacs of bird lungs or in the nasal passages and stomachs of bats. Some mite larvae of the suborder Prostigmata (order Acariformes) are parasitic on insects.

* * *