Beetles are used in fly fishing so I would think that live ones might be even better . Don't know about Japanese ones though.
Fly fishing example high visibility "Foam Beetle" link:
http://www.flyanglersonline.com/flyt...te/part42.html
More:
http://www.flyanglersonline.com/alca.../ac053104.html
http://www.flyanglersonline.com/flyt...22605fotw.html
http://www.flyanglersonline.com/flyt...80601fotw.html
http://www.flyanglersonline.com/alca.../ac060704.html
This article says that Japanese Beetle flies have been used with success:
http://www.flyanglersonline.com/feat...to/part16.html