They usually last all summer....KILL KILLL KILLLL!!!! I remember as a kid people taking gas (or other favorite accelerant) soaked rags tied to a stick and burning down the tents. That is a dangerous method if you used gas...I think there are other better ways to try to get rid of them, but my approach was to do the best you could and recognize that it is part of living in the midwest (and farther) with fruit trees...their favorite food (especially cherry, but I also saw them go after Walnut).

Hi michigoose, I've done lots of killing but our trees are to numerous. Live in the woods, so to speak. I did notice today that less leaves fell and less worms seen. I hope that is a good sign. NO fruit trees but many walnut. They also like maple.Gardening can be a challenge, can't it.