If your San Jose is in California, you don't have Japanese beetles.

Contact your county's Extension Service office for an ID when you take in samples. Locate your office with this map
http://www.csrees.usda.gov/Extension/

Here is a link that might be useful: locate your county's Extension Service office

The reports I have seen about "Bacillus thuringiensis japonensis" indicate it is giving very spotty results. A tried and relatively effective disease for Japanese Beetles is "Bacillus popilleae", Milky Spore Disease which is much more readily available.