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Entomology (Study of Bugs)/A wierd cocoon, maybe?


We moved in to a new house temporarly due to renovation in our flat.
In this rented house there a studio unit which is a bit newer then the rest of the house. when we got here there was a beginning of an ant infestion in the studio unit which we stopped with bug spray.
Later I noticed what I first thought was dust on the spiderwebs. There are like 10 or so of those cocoon stuff (attached picture). they are just a bit longer than a fingernail.
Also, worth to mention I live in Israel.


Hello, Assaf:

Thank you for including the image, and location, with your question.  Both help immensely.

The cocoon in the image is likely the "bag" of the "household casebearer" caterpillar, or something very closely related.  Here is a link with lots more information:

Ironically, the household casebearer feeds mostly on old spider webs!

Hope this helps.


Entomology (Study of Bugs)

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Eric R. Eaton


I answer insect and spider identification questions ONLY. Attach images if possible. No "what bit me?", "what do I feed this bug in captivity?", or science fair project questions please. NO TECHNICAL QUESTIONS ABOUT INSECT PHYSIOLOGY.


Principal author, Kaufman Field Guide to Insects of North America. Professional entomologist employed previously at University of Massachusetts, Chase Studio, Inc., and Cincinnati Zoo; contract work for West Virginia Department of Natural Resources, Smithsonian Institution, and Portland (Oregon) State University.

Author, Kaufman Field Guide to Insects of North America, Missouri Conservationist magazine, Ranger Rick, Birds & Blooms, Timeline (journal of the Ohio Historical Society). I have contributed to several books as well.

Oregon State University, undergraduate major in entomology, did not receive degree.

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One of the top 50 experts in all categories for, 2009.

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Principal author of the Kaufman Field Guide to Insects of North America, Smithsonian Institution (contract), Cincinnati Zoo (employer), Portland State University (contract), Chase Studio, Inc (employer), Arkansas Museum of Discovery (guest speaker). Currently seeking speaking engagements, leadership roles at nature festivals, workshops, and ecotours.

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