Serenthia femoralis var. confusa Puton, 1879b: 297 (transferred to laetum as var. by Reuter, 1885a: 43; upgraded by Horváth, 1905a: 556). LT (Péricart, 1977a: 319): macr. male, France, Gers; MNHN.
Serenthia femoralis var. antennata Horváth, 1905a: 556 (transferred to confusa as var. by Horváth, 1906a: 109, 114; syn. Péricart, 1977a: 329). LT (Péricart, 1977a: 319): female, Romania, Dobroudja, Constanţa; HNHM.
Serenthia femoralis var. thoracica Horváth, 1905a: 557 (transferred to confusa as var. by Horváth, 1906a: 109, 114; syn. Péricart, 1977a: 329). LT (Péricart, 1977a: 319): male, Hungary, Pakony; HNHM.
?Serenthia intermedia Wagner, 1941a: 20 (syn. Péricart, 1977a: 329). LT (Péricart, 1983: 526, as HT): male, Austria, Carinthia, Millstädter See; ZMUH.