Key to the species groups of the genus Sasajiscymnus Vandenberg, 2004

1. Outer arm of penis capsule distinct....................................................................... 2

- Outer arm of penis capsule inconspicuous or absent.......................................................... 4

2. Apex of penis complex................................................................................. 3

- Apex of penis simple................................................... Sasajiscymnus sylvaticus species group

3. Penis guide longer than parameres........................................... Sasajiscymnus hareja species group

- Penis guide as long as parameres........................................... Sasajiscymnus atypicus species group

4. Body length> 2.5 mm; paramere base greater or as great as 1/2 width of the penis base..................................................................................................... Sasajiscymnus amplus species group

- Body length <2.3 mm; paramere base markedly shorter than 1/2 width of the penis base.................................................................................................. Sasajiscymnus kurohime species group