Peter from Tustin writes
The Milky Spore is specifically designed to eliminate Japanese Beetle Grubs only. You would need to use a product like Imigold 0.5 Granules which is labed for the more commons species of grubs. To find out when the best time to apply is, you would need to contact your local Master Gardener to make sure you are apply the product at the right cycle in your area to get the most results from the product. Applying it too early in their cycle or too late can cause you to only see partial results.
Answer last updated on: 11/23/2013