Moved from Bothrideres.

Karl Stephan did the key and he sent me an annotated version many years ago before he died. There used to be only one species in your area, B. geminatus. Stephan split off a new species B. cryptus.
Here's how to separate them. The elytra have alternating intervals raised. One of the raised flat intervals starts at the humerus. The surface of this flat interval has punctures. If these punctures form a single row, then cryptus. If they form two rows then geminatus. I have about 50 specimens from all over the east and I have many in the category of uncommitted. I just looked at a "cryptus" and I admit that it is open to argument with a somewhat random location of punctures. A nicely lit photo of the flat humeral interval might show the pattern of punctures. Neither species is less common.