different between acarus vs acapus

English

Borrowed from New Latin acarus, from Ancient Greek ????? (ákari, “cheese mite, tick”), from ?????? (akar?s, “tiny”).

acarus (plural acari or acarina)

(zoology, acarology) Any member of the subclass Acari (aka Acarina): thus, a mite or a tick; specifically, any mite of the genus Acarus.
- 1868, Robert Niccol, The Sugar Insect, "Acarus Sacchari", Found in Raw Sugar, page 4,
  The number of Acari found in raw sugar is sometimes exceedingly great, and in no instance is the article quite free from either the insects or their ova (eggs).
- 2003, G. Leigheb, Mite bites, Andreas D. Katsambas, European Handbook of Dermatological Treatments, Springer, page 342,
  Besides the acarus of human scabies (Sarcoptes scabiei hominis) (0.3-0.5 mm), many other acari which are parasitic on animals or which infest various plant species, foods, organic waste or soil may occasionally attack man (facultative parasitism vs. obligatory parasitism in the case of scabies).

The term and its two plural forms match, and are potentially confounded with, three different taxonomic names for two related taxons: genus Acarus (Linnaeus, 1758) and subclass Acari (Nitzsch, 1818), aka Acarina. The subclass comprises all mites and ticks, while the genus is a particular group of mites.