Entomology (Study of Bugs)/Flying bug


I found this crawling on my floor. Should I be worried of a colony or it taking over my house? What kind of bug is it? I only found the one so far. My cat seemed to get bit or stung by it when he was trying to sniff it.


Thank you for including the image with your question.

The insect is a solitary wasp called a mason wasp, family Vespidae, subfamily Eumeninae, and probably Ancistrocerus for the genus.  Here's more:


These wasps are solitary, meaning each female wasp makes her own nest, usually inside a hollow twig, or some other pre-existing cavity.  Since there are no vulnerable larvae to defend, solitary wasps are not aggressive (unless physically grabbed, by you or your cat).

So, bottom line is:  no worries.  Mason wasps kill plenty of pest caterpillars to store as food for their offspring; and they also are fair pollinators of flowers.

Take care.


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.

Awards and Honors
One of the top 50 experts in all categories for AllExperts.com, 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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