Tarsalis

Tarsalis is a Latin adjectival epithet used in the scientific names of various organisms. In taxonomy, tarsalis generally denotes a relationship to the tarsus, the distal segment of an arthropod leg or similar appendage, hence meaning “tarsal” or “pertaining to the tarsus.” The epithet is employed across different animal groups and, less commonly, in other kingdoms, reflecting morphological or anatomical characteristics rather than evolutionary relatedness.

One well-known use of the name is in Culex tarsalis, the western encephalitis mosquito. This species is found across western North America and parts of neighboring regions. It breeds in standing or slowly moving water such as temporary pools and irrigation depressions and feeds on both birds and mammals. Culex tarsalis is noted for its role as a vector in the transmission of arboviruses, including Western equine encephalitis and St. Louis encephalitis, with the relative importance of transmission varying by locale and season.

Beyond Culex tarsalis, the epithet tarsalis appears in other taxa, illustrating how a single Latin descriptor can recur in diverse, unrelated lineages. The reuse of tarsalis reflects the descriptive, rather than systematic, function of species names in taxonomy.

In summary, tarsalis functions as a descriptive species epithet tied to the tarsus across multiple organisms, with Culex tarsalis serving as a prominent example due to its ecological role as a disease vector.