Lectotype, herein designated for the purposes of establishing a unique and unambiguous type, as the original description omitted any indication of number of specimens studied: of undetermined sex: [Peru:] “Pozuzu, M. Kirsch” / “Epierus ferrugineus” / “Staatl. Museum für Tierkunde, Dresden” / “LECTOTYPE Dégallier & Mazur, 2007” / “Kaszabister ferrugineus (Kirsch, 1873); SMTD.

ARGENTINA: Buenos Aires: Buenos Aires, 30.vii.1917, 9.vii.1923, 5.viii.1923 (4: MACN, NMNH); La Plata, viii.1912, nest of Solenopsis saevissima (2: NMNH); Rosas – F. C. Sud (7: NMNH); San Fernando, viii.1960 (1: NMNH). Mendoza: Mendoza, 20.x.1907 (1: ZMHB). BRAZIL: ‘Bahia’ (4: ZMHB). Distrito Federal: Brasilia, IBGE Ecological Reserve, 24.vi.1987, 13.v.1987, 7.vi.1987, 20.i.1998 (6: CIZUB, CHAT, CHND). Mato Grosso: Arenapolis, 22.viii.1972 (23: FSCA); Cáceres, 5.vii.1972 (1: FSCA); Cuiabá, 19.vi.1972 (1: FSCA); Mato Grosso Co., 25.vii.1972 (1: FSCA); Poconé, 23.iv.1972 (1: FSCA); Rondonópolis, 14–15.vii.1972 (3: FSCA); Rosario Oeste, 14.vii.1972 (1: FSCA). Pará: Belém, 2.vi.1985, flotation of the Solenopsis saevissima nest (identified by W. L. Overal) (1: CHND). Rondônia: Guajará Mirim, 1.ix.1972 (1: FSCA). São Paulo: São Simão, Usina Sta. Clara, 5.ix.1973 (3: FMNH). URUGUAY: Artigas: Ruta 30, km 45, 12.xii.1962, nest of Solenopsis saevissima (1: CHSM).

Frontal stria straight to evenly arcuate across front, not descending onto epistoma; fourth dorsal elytral stria complete and arched to suture; inner subhumeral elytral stria present in apical two-thirds; fifth elytral stria variable, from absent to present in apical one-half; sutural stria present in apical half; elytral ground punctures sparser and markedly reduced laterad fourth elytral stria; mesometaventral stria arched forward to about one-third from mesoventral margin; lateral metaventral stria reaching mesometaventral margin, nearly or fully meeting mesometaventral stria and postmesocoxal stria; inner postmetacoxal striae not forming a complete arc across anterior margin of abdominal ventrite 1, ending close to metacoxa; abdominal ventrites 2–4 with apical marginal stria; aedeagus rather short, parallel-sided, with apex subtruncate.

Known from Argentina (Mendoza, Buenos Aires), Brazil (Bahia, Distrito Federal, Mato Grosso, Pará, Rondônia and São Paulo), Peru (Huanuco) and Uruguay (Artigas).

As for Kaszabister barrigai, many records of Kaszabister ferrugineus from ‘ant nests’ almost certainly refer to Solenopsis invicta as host, while a few other labels specify Solenopsis saevissima (Smith). One specimen from Bahia in the Lewis collection bears a label “with an Aphaenogaster” (Formicidae). However, no host specimen is present for verification.

Mazur (1997) cites “Phelister marginicollis Bruch, 1914” as “nom. nud. - syn. nov., Wenzel in litt.”. Bruch (1914: 309) cites this as “Phelister marginicollis Lew. in litteris”. This appears to have been a species that Lewis intended to describe based on Bruch’s specimens, and he indicated such to Bruch. Specimens labeled “Phelister marginicollis Lewis” are present in the BMNH and NMNH. However, for whatever reason, the species was never formally published, so it is indeed a nomen nudum. In Bruch’s later works (e.g., 1935) he apparently realized that the species was not properly described and omitted it from his catalog.