Erimerinae has been proposed as a subfamily group name prior to Microdontomerinae and the latter was considered as a junior synonym of Erimerinae. A new genus, Perserimerus Lotfalizadeh & Rasplus, gen. nov., and three new species, Perserimerus marginalis Lotfalizadeh & Rasplus, sp. nov., Microdontomerus iriphagus Lotfalizadeh & Janšta, sp. nov., and M. quadrimaculatus Lotfalizadeh & Rasplus, sp. nov., are described from Iran. Diagnostic characters of the new genus and newly described species are provided and compared with morphologically similar genera and species. Microdontomerus iriphagus and M. quadrimaculatus were reared from oothecae of Iris oratoria (Linnaeus, 1785) (Mantodea) and galls of Stefaniola similata Mamaev, 1972 (Diptera: Cecidomyiidae) on Haloxylon ammodendron C.A. Mey, respectively. A key to the known species of Microdontomerus of Iran is provided.