TAXONOMY OF THE NEOTROPICAL GENUS AMERICABAETIS, NEW STATUS (INSECTA,EPHEMEROPTERA, BAETIDAE)

Americabaetis (Insecta: Ephemeroptera: Baetidae), previously considere d synonymous with Acerpenna, is reinstated and given generic rank. The genus differs from Acerpenna in lacking hindwings, gills on abdominal segment I, and a conical process between the male genital forceps, an d in possessing apically rounded gills an abdominal segment 7. The gen us has a general Neotropical distribution with a northern limit in eas t-central Mexico. Five new species of Americabaetis are described from South America: A. alphus, new species, from Argentina, Bolivia, Brazi l, Chile, and Paraguay; A. labiosus, new species, from Brazil, Paragua y, and Uruguay; A. longetron, new species, from Brazil, Paraguay, and Uruguay; A. maxifolium, new species, from Paraguay; and A. titthion, n ew species, from Brazil. Americabae:is boriquensis, new combination; A . intermedius, new combination; A. naranjoi, new combination; A. pletu rus, new combination; and A. robacki, new combination, are reviewed.