They are thinking it is from cicadas.
Just an F.Y.I...there is a disease that you can get called histoplasmosis from birds and bats droppings in the soil.
I had never heard of it. I suspect many Doctors are clueless as well and dont think of it when seeing the symptoms.
Brood X in yellow. Indiana and Pennsylvania.
They are certainly killing small branches of trees around here. Our yards are littered with fallen twigs full of dead leaves. And dead husks of cicadas. We live near a woods, and when they were first swarming up, the drone-scream-buzz was deafening.