The unique Neotropical species of the alderfly genus Protosialis van der Weele, 1909, P. bifasciata (Hagen, 1861), is herein transferred to newly described Caribesialis gen. nov. This new taxon proposed be sister clade + Sialis Latreille, 1802, after a phylogenetic analysis that included male genital characters scored on previous morphological matrix family. Also, Ilyobius nigrocephalus sp. nov...