Entomology (Study of Bugs)/GRASS WASP


QUESTION: There is something building a nest in the window frame where the storm window was not totally secured.  The 1 inch void allowed this bug to begin the nest today and it is growing by the hour.
Could you identify it and let me know the best route to get rid of it? thank you
The bug has yellowish legs with a brown or black dark stripe  in the middle of the leg.  smooth dark color with 2 pods and a tail which extends outward  It has Wings and is very long (1 inch?)
I took a picture with my ipad and will be happy to email it to you.
I saw the nest for the first time this AM and have been observing the bug building it bigger and bigger.  2 inches long around 8 and now at 1:37 it is 5-6 inches wide.


Sounds like a solitary wasp called the "grass-carrier," genus Isodontia .  They normally nest in natural cavities, but have found window tracks to their liking.  Here's an example:

Well, I'm getting a server error at Bugguide :-(


The above is a blog entry I did about these wasps.

I've also answered this kind of question recently, so you might be able to search my answers with the term "grass-carrier."

Do consider letting them be.  They are solitary and females won't sting unless you physically grab one (males do not have stingers).


---------- FOLLOW-UP ----------

QUESTION: Thank you for your help.
It's been fascinating watching the nest grow---but also gross since it's so close to our bedroom!
I sent a picture to my pest control company--they said it might be a mud wasp--  are they very different? They also will offered get rid me of it at a whopping cost of $285--thanks for providing info and blog---I can do it myself! (after I watch it a bit more!)


Here is the link I was trying to fetch the first time:


If the nest does not look like that then you have some other kind of wasp.  Without seeing an image I am only guessing.  Mud daubers don't usually nest in situations like that, but I can't exclude the possibility.  Here's what *they* look like:


There are still other possibilities.  Solitary wasps are highly diverse!


Entomology (Study of Bugs)

All Answers

Answers by Expert:

Ask Experts


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.

Past/Present Clients
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.

©2016 About.com. All rights reserved.