A new genus and species of asteraceae-inhabiting aphid (hemiptera: aphididae) from Costa Rica and Mexico

P. 323-331Ucrimyzus villalobosi Mier Durante & Pérez Hidalgo gen. n., sp. n. (Hemiptera: Aphididae: Macrosiphini) are described from apterous and alate viviparous females collected on species of genera Bidens, Schkuhria, Senecio and Stevia (Asteraceae: Asteroideae) in Costa Rica and Mexico. Principal components analysis (PCA) was done to verify that the studied aphids belong to a single species regardless of their geographical origin or host plant. Molecular analyses were carried out on the sequences of a fragment of the mitochondrial gene encoding for cytochrome c oxidase subunit 1 (COI) and of a fragment of the nuclear gene encoding elongation factor 1α (EF1α). The taxonomic discussion takes into account the conclusions of the molecular analyses and the morphologic study compared with other genera of Macrosiphini. The identification keys by Blackman & Eastop (2006) to aphids living on each mentioned plant genus are modified to include the new speciesS