On the ground (asphalt) under parking lot lights on a hot and humid night. This beetle is overall larger and darker, has deeper pronotal depressions, and has more prominent elytral costae compared to the few other Arhopalus rusticus obsoletus specimens that I have seen from Maryland and West Virginia. At fist, I thought it must be A. foveicollis. However, I believe the deeply lobed third metatarsal segment can be clearly seen in this specimen. The one thing that confuses me is that I can just barely see a few ocular setae and this character is also supposed to be distinctive for A. rustics obsoletus? Over the years (this comment updated March 2022), I have seen a few more A. rustics obsoletus in Maine, but I have yet to encounter A. foveicollis, even though I had presumed the latter species to be more typical of far northern forests. Both species are listed from Maine in the Checklist of the Beetles of Maine, USA by Majka, Chandler, and Donahue (2011).