Why did you mow at the lowest setting? Was that in prep for seeding?

Dig around in the surface of the soil. You are going to take a census of the grubs. If you have fewer than 12 grubs per square feet, then the lawn should survive this year's grub attack. More than a dozen grubs and you should do something. Do you already see damage or do you just see the grubs? If damaged, can you post pictures?

Timing for insecticide, seed, and fertilizer depends on what you use. If you use organic grub killers like beneficial nematodes or spinosad, you can apply seed the same day. Those two products cause a disease in the grubs and they stop feeding. If you use a chemical insecticide, then read the label regarding new seed.

Timing for new seed is just right. Now is the time.

Thank you replying.
Yes...I cut at the lowest level to prep for seed also in anticipation of applying a chemical insecticide. (works best on low lawns)
"Fewer than 12 grubs per/ sqft, lawn should survive?" I guess I may have over reacted by raking. Clumps of dead grass came up while raking so I assumed I needed remove as much as possible to prep for reseeding. Well, lesson learned.
If anyone knows of a particular chemical insecticide that will not affect seeds please make a recommendation.
Thank you again.

Here's another patch that doesn't look so bad.