New Species, Host Record, and Male Discovery for Three Messatoporus Cushman (Hymenoptera, Ichneumonidae, Cryptinae) from Brazil.

Messatoporus bisignatus Aguiar & Supeleto, sp. nov. is described and illustrated. The new species was extensively reared from trap nests colonized by Auplopus subaurarius Dreisbach, 1963 (Hymenoptera, Pompilidae), in an area of secondary Atlantic Forest in southern Brazil. Two other species, M. elektor Santos, 2013 and M. opacus Santos, 2013, were also reared from the same host, but in lesser numbers. The previously unknown males of M. elektor Santos, 2013, M. opacus Santos 2013 and M. unidentatus Santos, 2013 are described and illustrated. New females and significant morphological variation are reported for these species, previously known only from a few specimens. New geographical records are reported for M. unidentatus (Brazil, two localities in ES), M. elektor and M. opacus (Brazil, two localities in RS).