Key to the species of Physatocheila occurring in Japan

1 Paranotum completely covering pronotal disk in anterior part, touching median carina of pronotum, bulged upward, forming a cyst; subcostal area of hemelytron subvertical...................................... P. fieberi (Scott, 1874) (Fig. 5B)

- Paranotum incompletely covering pronotal disk in anterior part, not touching median carina of pronotum, not bulged upward, not forming a cyst; subcostal area of hemelytron subhorizontal................................................. 2

2 Lateral carinae of pronotum close to each other in anterior part; each paranotum widened posteriorly; outer margin of paranotum gently curved outward throughout its length............................................................. 3

- Lateral carinae of pronotum nearly parallel to each other throughout their length; each paranotum not widened posteriorly; outer margin of paranotum nearly straight throughout its length................................................. 4

3 General color black; median spine on head reaching level far remote from bases of frontal spines; rostrum reaching anterior part of metasternum; costal area of hemelytron slightly narrower than subcostal area at widest part of each; collected from Hovenia dulcis (Rhamnaceae) ................................................... P. nigrintegerrima sp. nov. (Fig. 1 A–D)

- General color brown; median spine on head reaching beyond bases of frontal spines; rostrum reaching posterior margin of abdominal sternite II; costal area of hemelytron wider than subcostal area at widest part of each; collected from Salix spp. ( Salicaceae)......................................................... P. distinguenda (Jakovlev, 1880) (Fig. 5A)

4 Body approximately 4.2 mm long from head to apex of hemelytron; costal area of hemelytron with 3 rows of areolae in basal part, 4–5 rows in middle part and 2 rows in apical part.............................. P. orientis Drake, 1942 (Fig. 5D)

- Body approximately 3.2 mm long from head to apex of hemelytron; costal area of hemelytron with 2 rows of areolae throughout its length............................................................................................ 5

5 Hood roof-shaped; lateral carinae of pronotum touching outer margin of paranotum at anterior end; subcostal area of hemelytron with 3 rows of areolae at widest part................................... P. miyatakei Miyamoto, 1964 (Fig. 5C)

- Hood low-dome-shaped; lateral carinae of pronotum not touching outer margin of paranotum at anterior end; subcostal area of hemelytron with 4 rows of areolae at widest part................................... P. veteris Drake, 1942 (Fig. 5E)