A new Neotropical species of Megamelus and the reassignment of Stenocranus maculipes (Hemiptera: Delphacidae)

We report on two species of Delphacidae from Argentine wetlands, Megamelus nigrifasciatus Mariani & Remes Lenicov sp. nov. and Megamelus macu- lipes (Berg) comb. nov. The first species was collected from Eryngium sp. (Apiales: Apiaceae) and was described from the brachypters of both sexes. The second one, Stenocranus maculipes (Berg, 1879) collected from Echinodorus grandiflorum (Alis- mataceae), is proposed as Megamelus maculipes comb.nov. The female macropter holotype is redescribed and the male and female brachypters are described for the first time. Geographic distribution and biological data of both species are reported. The genus Eryngium is cited for the first time as host plant for the genus Megame- lus. Additionally, a key is provided to distinguish among the seven South American species of Megamelus.