Ozark Lady, Please edit your post and attach the link from where you found the text.
While marketing hype like that makes it sound ecologically benign, I'm pretty sure that Japanese Beetles are not the *only* beetle larvae ("grubs" makes them all
sound bad, doesn't it?) this bacteria infects. Some "innocent" baby beetles may be dying grisly deaths as well.
Also, Soil Foodweb-wise, it might not be best course of action to artificially super-boost a single strain of soil bacteria.
That said, I did apply Milky Spore a few years ago in a limited area surrounding where a wild grape vine grew and attracted an unbelievable number of JB's.
It's a tricky issue that I haven't reconciled yet.