ACARI

also called Acarida, or Acarina, subclass of the arthropod class Arachnida that includes the mites and ticks. The acarids may be separated into three orders, Opilioacariformes, Parasitiformes, and Acariformes, consisting of six suborders and about 428 families. Additional reading The acarids (mites and ticks) are examined in Tyler A. Woolley, Acarology: Mites and Human Welfare (1988), a comprehensive treatment of the entire field; G.W. Krantz, A Manual of Acarology, 2nd ed. (1978), a systematic arrangement; Burrus McDaniel, How to Know the Mites and Ticks (1979), a comprehensively illustrated work of U.S. mites and ticks; W. Helle and M.W. Sabelis (eds.), Spider Mites: Their Biology, Natural Enemies, and Control, 2 vol. (1986); Asher E. Treat, Mites of Moths and Butterflies (1975), presenting almost 100 species classified as scavengers, hitchhikers, or parasites and discussed on a global basis; Frederick D. Obenchain and Rachel Galun (eds.), Physiology of Ticks (1982), a collection of review articles; and John R. Sauer and J. Alexander Hair (eds.), Morphology, Physiology, and Behavioral Biology of Ticks (1986). Nixon A. Wilson