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Owlet Moths Laying Eggs

One morning multiple 1”-2” white blotches appear on the screening of your porch or windows.  They weren’t there the previous day, so they had to have been deposited during the night.  What nocturnal creature is responsible and what exactly are they?

A close look reveals that each white patch consists of hundreds of minuscule white balls – eggs that an insect must have deposited.  Their size, shape and coloring indicate that they were most likely produced by Owlet Moths or noctuids, members of the Noctuidae family.  Owlet Moths make up over 25% of all butterflies and moths — there are 75,000 known species worldwide with thousands yet to be identified. Most adults are a fairly drab shade of brown and are well camouflaged with lines and spots that resemble tree bark or bird droppings. (Moth coloring often resembles the bark of the food plant its larvae prefer.) Owlet Moth larvae are relatively hairless and are referred to as cutworms or armyworms (they can occur in destructive swarms and cut the stems of plants). Several species are serious crop or garden pests.

A majority of the moths in this family are nocturnal and are attracted to light.  After mating, female Owlet Moths produce between 300 and 1,500 eggs, depending on the species.  Newly laid eggs are spherical and often cream color but may turn yellow, orange, pink, red or gray within a day. Those laid this fall will overwinter and larvae will hatch in the spring.

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4 responses

  1. Alice

    Don’t think I’ve ever seen that. That’s a lot of eggs!

    September 18, 2020 at 9:11 am

  2. Well we have tons of these everywhere! Franklin, Massachusetts!

    September 18, 2020 at 1:42 pm

  3. Barry Cottam

    Thanks for this, Mary! I’d seen these back in 2017 on our porch screen and didn’t know where to begin figuring out what they were. The info that it’s a noctuid’s eggs was the key, leading to tracks and sign of insects guru Charley Eiseman’s series of photos on BugGuide, beginning at He managed to raise them and shows the larval stages, plus ID’d the moth, Noctua pronuba, the Large Yellow Underwing. Great to have a mystery solved!

    September 18, 2020 at 5:06 pm

  4. Philip Hamilton

    Hi Mary- I’m trying to make another donation and the donate button isn’t working for me. It says the organizations account is inactive.

    September 18, 2020 at 8:14 pm

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