Four Silpha species from Northeast Asia compose the S. carinata group (sensu Háva et al. 1999). They may be discriminated using the following key:
1 Small impunctate field behind eyes absent................................................................................................................... 2
- Small impunctate field behind eyes present................................................................................................................. 3
2 Antennal segment VIII not longer than IX. Median lobe of aedeagus with sides constricted medially (Portevin 1926: Fig. 55; Nakane 1955: Fig. 9; Háva et al. 1999: Fig. 28); parameres straight. Distribution: Russia (from East Sayans through East Siberia to Primorsky Kray, Sakhalin, Moneron Is. and South Kurils (Iturup Is., Kunashir Is., and Shikotan Is.)), Mongolia, China (Beijing, Hebei, Heilonjiang, Jiangxi, Jilin, Nei Mongol, Shaanxi, and Shanxi), the Korean Peninsula, Ulleung-do Is. and Jeju-do Is., and Japan (Hokkaido, Rishiri-tô Is., Rebun-tô Is., Teuri-tô Is., Yagishiri-tô Is. and Okushiri-tô Is.) ........................................................................................................ S. perforata Gebler
- Antennal segment VIII distinctly longer than IX. Median lobe of aedeagus parallel sided (Portevin 1926: Figs. 58– 59; Šustek 1983: Figs. 53–56; Háva et al. 1999: Fig. 31); parameres very sinuate. Distribution: from Europe to Transbaikalia and Central Asia, including Mongolia and westernmost China .................................. S. carinata Herbst
3 Pronotum densely punctate in its central part. Median lobe with apex hook-shaped in lateral view (Kusakari 1993: Figs. 9–12; Háva et al. 1999: Figs. 29–30). Apex of male metatibia projected at the inner angle (Fig. 14). Distribution: Japan (Honshu northeast of the Kii Mts., Sado Is.) ........................................................... S. longicornis Portevin
- Pronotum sparsely punctate in its central part (e. g., Háva et al. 1999: Fig. 20). Median lobe gently turned upward in apical part, the apex rounded in lateral view (Háva et al. 1999: Figs. 25 –27, 38– 43). Apex of male metatibia simple. Distribution: China (Shaanxi) ................................................................. S. businskyorum Háva, Schneider et Růžiċka