This is due to grubs…… right?

most likely the holes were created by birds, trying to get to the grubs.

you can use a grub killer like scotts grub ex now or wait until june/july to apply something with imidacloprid. If you have a bad grub problem, which it looks like you do, I would do both.

Thank you - I will do both. Can I apply weed and feed with the grub ex? Or do you think I should hold off?

Depends on how they are to be applied/watered in.. check their directions but I think you will probably have to apply them separately.

The grub ex needs to be watered in to get the chemicals down into the soil to the level of the grubs to be effective.
They recommend you apply it and then water it in right away with at least .5" water (I think), or within 24 hours.

Most granular weed n feed products tell you to apply it to a wet turf, and then allow it to dry.

So they probably shouldn't be applied all at once.

to be safe, I'd apply the grub ex and then water it in right away. And then apply the weed n feed while the turf is still wet.... then allow it to dry. which I guess, would technically be two separate applications, but could be done back to back, same day.

Thank you very much!