Another reason for problems can be Mole Crickets. The adults are large beasties that burrow under the lawn and eat the roots. The babies are tiny and black and jump about in front of you as you walk, as they get older they turn brown.
Known here as Danaburnu. You need to ask for Danaburnu ilacı. They told us to mix the powder with bran or flour. This made a right mess. One place had a fluid, and I wonder if that might be better, but it is supposed to be used late spring, I think, so, it might be too late for this year as it works on the babies and maybe they are too big now.....