Katydids are in the cricket family, I think, but they look more like grasshoppers to me. From what I have observed, they will eat the leaves of anything and everything, even plants that nothing else seems to bother. Maybe I'm exaggerating but it seems like I find them munching all different types of plants, leaves and flowers. I've never really thought of them as friends but they probably make good food for amphibians and my chickens think they are quite tasty. The Mississippi Kites find the grasshoppers desirable so maybe they like the Katydids too. I've never witnessed any beneficial insects (Assassin bug, spider, Praying Mantis) take a Katydid for food, but that doesn't mean it doesn't happen.
Now that I think about it, I haven't seen very many katydids this year but I have seen more frogs, lizards and birds. Bats too.
In any event, I want to add that I find it works out best when nature takes its course and over the years. Here, everything is balancing out in a good way.
