Key to the species of the genus Mesostrix
1 Elytra with red maculae. Pygidium with elevated margin...................................... M. bimaculata sp. n.
- Elytra without maculae. Pygidial margin not elevated......................................................... 2
2 Fourth dorsal stria abbreviated basally. Pygidial segments reddish............................... M. pentatoma Mazur
- Fourth dorsal stria complete basally. Pygidial segments black.................................... M. nigropyga sp. n.