Revision of Nearctic species of Cerodontha ( Cerodontha ) (Diptera: Agromyzidae)

Abstract The Nearctic fauna of the subgenus Cerodontha ( Cerodontha ) Rondani is revised and contains 10 species: C . adunca sp.nov . (Mexico), C . dorsalis (Loew) (widespread Nearctic, eastern Palaearctic, Neotropical), C . gracilis Spencer (western Nearctic), C . inflata sp.nov . (Mexico), C . occidentalis Sehgal (northwestern Nearctic), C . occidoparva sp.nov . (western Nearctic), C . toluca sp.nov . (Mexico), C . trispinata Spencer (Mexico), C . trispinella Spencer (Mexico), and C . trispinosa Spencer (Mexico). All Nearctic species are described and illustrated and a key to species is provided. There are two colour forms of the widespread Nearctic species C . dorsalis : a pale eastern form and a dark western form, although there is overlap in the geographic distribution of the two forms and intermediates exist. The six Mexican species are known from a total of only nine specimens, suggesting that the diversity of this subgenus in Mexico and Central America may be higher than currently known.