Question
Kenneth,

It is nearing the end of April and grubs have overtaken my front lawn (Michigan).  The yard is completely dirt and needs to be re-seeded.  Is it okay to plant grass seed now, along with putting an insecticide down (containing Merit or Triumph) and then treat in the fall?  I am not sure when it is safe to begin re-planting grass seed.  Any advice would be greatly appreciated.  

Answer
I would apply Triumph now and seed at the same time. The grubs can be very difficult to eradicate in spring but if you are going to battle them now, then Triumph (isazophos) would be my choice. In July apply Merit (imidacloprid) which will handle the second generation after egg laying this summer (for the grubs not killed with isazophos. Grubs are hard to kill early in spring but there is no reason to wait until fall)

Replanting grass seeds now are fine. If you find that results were not ideal, you can overseed the (sparse) lawn in september again. But if you want to seed prior to summer, this would be the time. Grubs wont eat seeds, and using Triumph now and Merit in July you should be ok.