Moved from Prionus.

This is a female Prionus pocularis (Prionus imbricornis female would be the other option, but there are only 12 antennal segments). This is a great record! In my opinion, P. pocularis is predominantly a coastal plain species found in sandy pine forests and is rarely seen north of Maryland. In addition to that, females, despite their gigantic size, are secretive and hard to find. Even though multiple sources report this beetle as occurring in the Northeast, virtually every northern specimen of "pocularis" that shows up on BugGuide has turned out to be a misidentified Prionus laticollis (typically a light brown teneral specimen) or Orthosoma brunneum. But, there are some recent correct BugGuide records from Long Island and now we have your record here from Cape Cod. Really awesome - thanks for posting!

Moved from Prioninae.

Moved from ID Request.