Key to the species of Physatocheila occurring in Japan

Modified after the keys provided by Yamada & Tomokuni (2012) and Souma (2019).

1 Paranotum completely covering pronotal disc in anterior part; subcostal area of hemelytron subvertical................. 2

- Paranotum incompletely covering pronotal disc in anterior part; subcostal area of hemelytron subhorizontal............. 4

2 General color ashen; pubescence on pronotum more than 0.5 times as long as diameter of compound eye; costal area of hemelytron more than 0.5 times as wide as discoidal area at widest part............................................................................................................. P. euthenia (Drake & Ruhoff, 1965) comb. nov.

- General color brown; pubescence on pronotum less than 0.5 times as long as diameter of compound eye; costal area of hemelytron not more than 0.5 times as wide as discoidal area at widest part............................................. 3

3 Rostrum reaching posterior margin of mesosternum; paranota touching each other, concealing median carina of pronotum; cyst of paranotum not concave in posterior part; collected from Causonis japonica (Vitaceae) ................................................................................................... P. chiniana (Drake, 1942) comb. nov.

- Rostrum reaching posterior margin of metasternum; paranota not touching each other, touching median carina of pronotum; cyst of paranotum concave in posterior part; collected from Boehmeria species (Urticaceae) ......... P. fieberi (Scott, 1874)

4 Paranotum bulged upward in posterior part, forming a cyst; costal area of hemelytron with a single row of areolae in apical part.................................................................. P. consueta (Drake, 1948) comb. nov.

- Paranotum not bulged upward in its entire length, not forming a cyst; costal area of hemelytron with 2 rows of areolae in apical part................................................................................................ 5

5 Lateral carinae of pronotum close to each other in anterior part; paranotum widened posteriorly; outer margin of paranotum gently curved outward in its entire length.................................................................. 6

- Lateral carinae of pronotum nearly parallel to each other throughout their length; paranotum not widened posteriorly; outer margin of paranotum nearly straight in its entire length....................................................... 7

6 General color black; median spine on head reaching level far remote from bases of frontal spines; rostrum reaching middle part of metasternum; costal area of hemelytron slightly narrower than subcostal area at widest part; collected from Hovenia dulcis (Rhamnaceae) ............................................................... P. nigrintegerrima Souma, 2019

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

7 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

- Costal area of hemelytron with 2 rows of areolae in its entire length............................................. 8

8 Lateral carinae of pronotum touching outer margin of paranotum at anterior end; costal area of hemelytron as wide as subcostal area at widest part; subcostal area with 3 rows of areolae at widest part.................... P. miyatakei Miyamoto, 1964

- Lateral carinae of pronotum not touching outer margin of paranotum at anterior end; costal area of hemelytron narrower than subcostal area at widest part; subcostal area with 4 rows of areolae at widest part.................. P. veteris Drake, 1942