I was just getting into position to take another photo, when the damn thing dropped itself off the plant and disappeared among the dead leaves on the ground. When these things play dead there is no spotting them!

Actenicerus pruinosus

Coleoptera: Elateridae
Actenicerus pruinosus
Speckled Click Beetle (lit.) = shimofuri-kometsuki

Location: fureiai-no-mori Forest Park in Munakata (map here)