The status of R. interrupta in relation to R. parva is still a point of discussion. Based on reserche of Wigham (1975), R. interrupta is considered by many authors as a variety of form of R. parva (Fretter & Graham, 1778; McKay & Smith, 1979). Nordsieck (1968) and Verduin (1976) think however that R. interrupta and R. parva are two different species. Both species have a sympatric appearance.