Admittedly entomology isn't my primary pursuit, but given a guess I'd think it looks like a cicada wing. But if so it should be much larger. On the other hand it also looks like a termite wing. Or, well, probably a lot of possible stuff. If it is truly a struck through and not just a stain or glue impression or whatever, then it would be worth getting an ID on it for sure. The way I am seeing the marking cross the devices I am in doubt that it is a struck through at this point but look forward to following this one.