Walter, David Evans Department of Invertebrate Zoology, Royal Alberta Museum, Edmonton, Alberta, Canada.
Last reviewed:October 2019
- Body plan
- Development, reproduction, and genetics
- Ecology and distribution
- Related Primary Literature
- Additional Reading
A taxon of arachnids (traditionally considered a subclass of the Arachnida), comprising the mites and ticks. The Acari (also Acarina) consist of two superorders of small to minute arachnids. They have two body regions (Fig. 1)—a headlike gnathosoma (“jaw body”) or capitulum (“little head”) and a sacklike idiosoma (“special body”)— and a hexapod (six-legged) larval stage (Fig. 2b). The smallest known mite is about 0.08 mm (0.003 in.) in length as an adult, whereas the largest, a tick fully engorged with blood, is about 30 mm (1.2 in.). More than 50,000 species have been described, including many that have importance in a number of areas: medical [ticks, scabies, house dust mites, and chiggers (Fig. 2b)], veterinary (mange mites and rodent mites), agricultural (spider mites, poultry mites, and stored-product mites), and ecological [oribatid mites (Fig. 2a), mesostigmatid mites (Fig. 1), and water mites]. Perhaps as many as 1 million species are alive today. Current research indicates that the two superorders (Acariformes and Parasitiformes) may be only distantly related; that is, mites consist of two distinct and separate groups of arachnids. See also: Arachnida
The content above is only an excerpt.
for your institution. Subscribe
To learn more about subscribing to AccessScience, or to request a no-risk trial of this award-winning scientific reference for your institution, fill in your information and a member of our Sales Team will contact you as soon as possible.
to your librarian. Recommend
Let your librarian know about the award-winning gateway to the most trustworthy and accurate scientific information.
AccessScience provides the most accurate and trustworthy scientific information available.
Recognized as an award-winning gateway to scientific knowledge, AccessScience is an amazing online resource that contains high-quality reference material written specifically for students. Contributors include more than 9000 highly qualified scientists and 43 Nobel Prize winners.
MORE THAN 8700 articles covering all major scientific disciplines and encompassing the McGraw-Hill Encyclopedia of Science & Technology and McGraw-Hill Yearbook of Science & Technology
115,000-PLUS definitions from the McGraw-Hill Dictionary of Scientific and Technical Terms
3000 biographies of notable scientific figures
MORE THAN 19,000 downloadable images and animations illustrating key topics
ENGAGING VIDEOS highlighting the life and work of award-winning scientists
SUGGESTIONS FOR FURTHER STUDY and additional readings to guide students to deeper understanding and research
LINKS TO CITABLE LITERATURE help students expand their knowledge using primary sources of information