I'm writing you from Italy, in case this additional information may help in identifying the cocoons (?) in the picture I am sending you. As you will see there are a series of them, and I found them exactly the same way as you see them in the picture. They were all empty but we cracked open one of them (they had a tough, gray and rough exterior) and found a long brown semi transparent wing inside. I have no idea what this is and of what insect it might have come from. They were all stuck on our curtain in the second floor of the house.

I'm sorry I couldn't tell you for sure, but it looks to me like a silkmoth of sorts.