Key to species of Pantisarthrus (Modified from Van Rossem, 1987)

1 Mesoscutum with a median longitudinal sharp groove.................................. P. isolatus (Benoit)(Oceanic)

- Mesoscutum without a median longitudinal sharp groove...................................................... 2

2 First metasomal tergite long, 2.7–3.0× as long as its apical width, with rough and irregular longitudinal sculpture; profile of tergite trapezoidal; claws of front legs conspicuously stronger than those of mid and hind legs; ovipositor 0.16× length of hind tibia.............................................................. P. gracilis Van Rossem (Western Palaearctic)

- First metasomal tergite length no more than 2.5× as long as apical width; sculpture variable, in some males surpassing 2.5× but in these case the sculpture is coriaceous.................................................................... 3

3 First metasomal tergite never coriaceous................................................................... 4

- First metasomal tergite coriaceous........................................................................ 6

4 First metasomal tergite rugose, with two parallel longitudinal carinae from apex to base (Fig. 24)............................................................................................... P. paraitinga sp. nov. (Neotropical)

- First metasomal tergite mostly smooth basally, with posterior half sculpture varying, and with two converging longitudinal carinae (Figs 6, 9, 10, 18)............................................................................... 5

5 Body mostly black; metasomal tergite 2–7 dark brown, metasomal tergite 2 and 3 with a yellow stripe between them (Figs 11, 13).................................................................. P. flavocingulatus sp. nov. (Neotropical)

- Body dark brown; metasomal tergite 2–7 light brown, metasomal tergite 1 and 2 with a white stripe at the apex (Figs 1, 3)........................................................................... P. communis sp. nov. (Neotropical)

6 Second metasomal tergite and following polished with some irregular puncture, mesoscutum strongly convex, prescutellar groove conspicuously deep........................................... P. rudepunctatus Strobl (Western Palaearctic)

- Second metasomal tergite and others polished without punctures................................................ 7

7 Section gh of radiella absent; first metasomal tergite 2.0–2.6× as long as apical width................................................................................................. P. dispar Van Rossem (Western Palaearctic)

- Section gh of radiella present; first metasomal tergite 1.4–2.3× as long as apical width............................... 8

8 Section gh of radiella equal to or slightly shorter than section dg............................................................................................ P. lubricus (Förster) (Eastern Palaearctic, Western Palaearctic, Nearctic)

- Section gh of radiella longer than section dg.......................... P. luridus Förster (Western Palaearctic, Nearctic)