Simple answer is you should never pretreat for grubs.

Grubs come from several species of beetles including Japanese beetles and June bugs. Once the eggs are in the soil, they go through their life cycle, become beetles, and then fly away. There is no residual effect from grubs.

You can generally predict whether you will have grub damage in your lawn. If you get swarms of beetles around your porch lights in May and/or June, then set your calendar ticking. That gives beetle eggs time to hatch and become larvae (grubs). A month later you can dig up 1 square foot of turf looking for them. If you find fewer than a dozen grubs, cover them up and leave them alone. There's no need to poison all the insects in your landscape just to kill a few. Normal grass can tolerate that many without showing any damage. If you see an uncountable mass of grubs, then spray. It is very unusual for a lawn to be attacked by grubs two years in a row.