I tied some ladybug flies for a friend a couple of years back. He said a lake he hikes to has a lot of ladybugs hitting the water and the trout would not touch the flies he had on hand. He told me he caught several trout with the ladybug flies on his next trip. Before giving the ladybug flies to him, I tried them at a local pond and caught some bass and bluegill with them. I think they would work for most fish from spring through fall.