|My lawn has two problems: First, there is a small area that appears to be dead and I see insects which resemble large mosquitoes flying around and on the lawn. I was told these might be crane flies or leatherjackets. The other problem is the yellow mottling in my lawn--no specific patches; for the most part it is throughout. Could this be rust, and if so, what to do? We put our lawn in in the form of sod a few years ago, but unfortunately I don't know what kind of grass it is. It has always looked great until now.