Lygaeus ambiguus Fallén, 1807: 89. STS: male, female, Sweden, Westrogothia [= prov. Västergötland] and Scania [= prov. Skåne]; MZLU.
Phytocoris mutabilis (non Fallén, 1807): Fallén, 1829: 98 (part.). Misidentification (see Reuter, 1873: 20).
Phytocoris betuleti (non Fallén, 1826): Zetterstedt, 1838: 274. Misidentification (see Reuter, 1873: 20).
Capsus obscurus Kirschbaum, 1856: 252, 322 (syn. Kirschbaum, 1856: 279, suspected; Fieber, 1861: 304; Wagner, 1939b: 49). STS: male, Germany, Wiesbaden; MWNH.
Poeciloscytus (Systratiotus) diversipes Horváth, 1885: 323 (syn. Horváth, 1888: 188). ST(S): female, Slovakia, Kezmarok; HNHM.
Psallus ambiguus f. bicolor Stichel, 1933: 261 (junior primary homonym of Psallus bicolor Jakovlev, 1880). For var. γ (part., male) in Reuter, 1878a: 106.
Psallus ambiguus f. translucida Stichel, 1933: 261, 263. For var. γ (part., female) in Reuter, 1878a: 106.
Psallus ambiguus f. inconspicua Stichel, 1933: 263. For var. β in Reuter, 1878a: 106.
Psallus ambiguus f. similis Stichel, 1933: 263. For var. δ in Reuter, 1878a: 106.
Psallus ambiguus f. bicincta Stichel, 1956: 281. New name for f. bicolor Stichel, 1933 (see Stichel, 1958a: 811).
Psallus (Mesopsallus) pseudoambiguus Wagner, 1970e: 300 (syn. Rizzotti Vlach, 2000b: 20). HT: male, Italy, Lucania, Apennines, Laghi di Monticchio; ZMUH.