Q.I Have Grub Worms In My Lawn In South Western Pa. What Should I Apply To Kill Them And Should I Scrape Off Dead Grass?
When should I reseed the bare spots

Certified GKH Gardening Expert
Yes, it is recommended to scrape off the dead grass and reseed. The timing depends on which grass you choose.
https://www.gardeningknowhow.com/lawn-care/lgen/lawn-seeding-tips.htm
Getting rid of them is best done, naturally. Neem Oil, milky spore, and beneficial nematodes are helpful. There are chemical options too.
This article will help:
https://www.gardeningknowhow.com/plant-problems/pests/insects/get-rid-of-grub-worms.htm