See notes under

for identification details. Note there are three very prominent punctures with setae along the lateral pronotal margin (compared to the two, less distinct [in my opinion], punctures of
Dicaelus furvus). Also, note the mostly flat triangular dorsal surface of the left mandible. The arrow points out a shallow depression in roughly the same location where
D. furvus has a slightly raised ridge. Also, take care that the medial tooth of left mandible is NOT the same thing as the "dorsal tubercle" in Ball or Ciegler's keys. That really confused the heck out of me for some time!