Key to Boundarus species (male)

1. Forewing generally black; apical processes of aedeagus short, about one fourth length of aedeagal shaft ................... ..................................................................................................................................................... B. nigronotus sp. nov.

-. Forewing generally yellowish brown with black patches; apical processes of aedeagus long, exceeding one fourth length of aedeagal shaft................................................................................................................................................. 2

2. Aedeagus with anterior processes near middle of shaft not hook-like in lateral view; apical processes about half length of the shaft ................................................................................................................................... B. trimaculatus

-. Aedeagus with anterior processes near middle of aedeagus hook-like in lateral view; apical processes one third length of the shaft ......................................................................................................................... B. ancinatus sp. nov.