An examination of the north American aphid species currently placed in Ovatus van der goot (Hemiptera : Aphididae) with the description of a new genus

The current placement in Ovatus of four endemic North American aphid specie s is critically examined. Results of cladistic analyses clearly indicate th at these four species are not congeneric with Palearctic Ovatus and that th ey are more closely related to Myzus Passerini. Cladistic evidence is provi ded to justify the erection of a new genus, Abstrusomyzus n. gen., for the four endemic North American species formerly placed in Ovatus. This resulte d in four new combinations: Abstrusomyzus leucocrini (Gillette & Palmer) n. comb., Abstrusomyzus phloxae (Sampson) n. comb., Abstrusomyzus reticulatus (Heie) n. comb., and Abstrusomyzus valuliae (Robinson) n. comb. Informatio n on each of the four species is compiled and presented. Illustrations are provided, along with a key to the species of the new genus and notes on the single remaining species of Ovatus in North America, Ovatus crataegarius ( Walker).