This would work:
destViewController.title = [NSString stringWithFormat:@"%@ Areas", destViewController.stateName];
Update for comment, you could also do:
NSString *newString = [destViewController.stateName stringByAppendingString:@"Areas"];
I prefer the former simply because I think its easier to add and remove stuff to your string. But that being said, if its not going to change much the latter is a bit more succinct.