Get a bottle of Bayer tree & shrub for grub worms.
The ingrediant IMIACLOPRID is the same ingrediant that Bayer puts in its pet products for fleas. Its just not as concentrated.
I've been using it for several years on our dogs. I put 12cc on our big dogs and go down from there depending on size of the dog. Our rat terrier gets 4cc. I put it on just like you would the expensive stuff Bayer sells.
It won't touch ticks, but it works on fleas. Once every month.

It works and its a LOT cheaper than the other stuff.