I live in University Park in Maryland. I noticed a large cocoon or egg sac under my deck yesterday Jan 6, 2018. it is about 3 inches wide by 4 or 5 inches long. I took photos. I am not sure if the cocoon is still active as part of it seems to be hanging out? I do know it was not under my deck this summer. I was checking for wasp nests. Can you help identify it? I am thinking Giant Silk Moth?
What a nice looking cocoon! Yes, this looks like it is from a type of giant silk moth, possibly a Cecropia moth. It probably is still active. Just leave it as. It is not harmful. The adult moth will chew through the cocoon when it emerges in the spring.
Thank you! I wondered what the long hanging thing of silk stuff is that is near the main cocoon? Is that normal? Thank you!
Yes, that is normal. It looks like a portion of the silk they used for attachment just fell down.