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Polyphemus Moth Cocoon

Congratulations to Stein, the first person to correctly identify Monday’s Mystery Photo as the cocoon of a Polyphemus Moth!

The Polyphemus Moth is one of our giant silk moths, spinners of the largest cocoons in North America.  Leaves are often woven into the surface of the cocoon in which the Polyphemus pupa spends the winter.  Unlike most other giant silk moths’ cocoons, the Polyphemus Moth cocoon lacks an escape “valve” at one end. In order to emerge (as an adult) from the cocoon the summer after it spins it, the moth secretes an enzyme that digests and softens the silk at one end. Then it moves about the cocoon in a circular pattern, tearing the softened silk with two spurs located at the base of each wing on its abdomen. Eventually it escapes by splitting the silk and pushing the top up.

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5 responses

  1. Alice

    Amazing that the pupa spend the winter in a cocoon and interesting info on how they eclose (or do only butterflies eclose?).

    October 7, 2019 at 8:29 am

    • Hi Alice,
      Yes, both butterflies and moths eclose!

      October 7, 2019 at 1:57 pm

      • Alice

        Thanks, Mary! It’s good to be correctly informed. Grand-daughter, Olive, moved some pillows, near her swingset this am, that were laying on the grass, lots of slugs, she knew that one pile was slug eggs & then spotted a ‘Spotted Salamander’, only about 2″, maybe 2 1/2 with the tail. …. so little & precious! I took a few pictures.

        October 7, 2019 at 2:10 pm

  2. Jane Marshall

    An aside: Why am I still seeing so many Monarch Butterflies?
    I am in the Johnson area.

    October 7, 2019 at 9:22 am

    • I wish I could tell you, but I honestly don’t know, Jane. I agree that there are some mighty late monarchs. If I learn why, I will get back to you!

      October 7, 2019 at 1:56 pm

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