1. Pronotum with a short, elevated, longitudinal keel separating the callosities (Fig. 11). Posterior margin of abdominal tergites III–IV unarmed.......................................................................................2.
– Pronotum without elevated keel between callosities. Posterior margin of abdominal tergites III–V armed with minute tubercles (Fig. 12)............................................................................................3.
2. Head and pronotum with marmorated pattern dorsally. Trifurcate carina of scutellum interrupted by punctures basally............................................................. Nannogermalus marmoratus Kóbor & Kondorosy, 2020
– Head and pronotum not marmorated; pronotum with brownish longitudinal lines near lateral margin (sometimes inconspicuously faded). Trifurcate carina of scutellum not interrupted basally........................... Nannogermalus webbi sp. nov.
3. Pronotum with a wide, brown longitudinal band medially. Punctation of pronotum posteriad to callosities irregular, relatively sparse.................................................................... Nannogermalus herczeki sp. nov.
– Pronotum with two thin brown longitudinal lines submedially. Punctation of pronotum posteriad to callosities even, dense......................................................................... Nannogermalus pallgergelyi sp. nov.