Posed. There is a droplet of water on the tip of the abdomen. Length measured by photographing adjacent to a scale. I presume this is a male due to the enlarged mandibles--some other examples we have in the Guide have smaller mandibles, and references indicate there is sexual dimorphism. This is an example from North Carolina--so far we just have examples from the Northeast.
This beetle emerged from a large jar, kept outside in the shade, where I am keeping a bunch of natural rotting wood substrate including, 2-3 pupa of presumed Lucanus species
. (I expect these in July.) It is likely this was from the smaller larva I photographed, thinking it was a small Lucanus
, and later found in a pupation chamber :
I'm not sure I took enough detailed photos of each grub to see if there were any differences, but the small size (40 mm, and thin) of those two, along with the adult emergence, makes me pretty confident in the placement with Platycerus virescens