Knowledgebase

What type of cocoon is this? #604334

Asked October 26, 2019, 7:05 PM EDT

I was exploring around my house and I found this attached to my siding. I have no idea if this is a cocoon but it's pretty large in size, roughly about the size of an adult palm. 

It's kind of cool, but I'm kind of scared about what could be in there. It's also October, but I don't know if that would factor in with anything. 

Osceola County Iowa

Expert Response

Hello:

Thank you for your message and for contacting Iowa State University. The cocoon on the side of your house appears to be the cocoon of the cecropia moth. This is a moderately common, very large moth in Iowa and the eastern U.S. Cecropia moths and caterpillars are not harmful.

Cecropia cocoons are usually attached to twigs as you'll see in the photos at this website. This link will also show what the large, attractive caterpillar looked like back in the summer.  https://bugguide.net/node/view/4625/bgimage

The cecropia is adapted to survive the winter in the cocoon stage.  No action is needed to help this individual make it through the winter to emerge as an adult moth next May.

Here is our online article for more information.  https://hortnews.extension.iastate.edu/cecropia-moth

Websites for technical details.  https://bugguide.net/node/view/4625

https://www.butterfliesandmoths.org/species/Hyalophora-cecropia

Thanks.

Donald Lewis

Donald R. Lewis Replied November 08, 2019, 9:42 AM EST

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