Entomology (Study of Bugs)/Black wasp


Black wasp
Black wasp  

Hi Eric!
I just posted to your wasp blog about my wasp situation. Attached are some pictures of a dead one.we have so many 30-40 I'm just not sure what to do about them? If they are good for my farm and flower/vegetable gardens I don't want to eradicate all of them but they are really stirred up and I'm not sure what to do with my grandchildren coming. We have also knocked down a couple of paper nests that they have been do rebating around. But those are not big enough houthese swarms!

Hi, Debbie:

Yes, just as I suspected from your post to my blog:  these are *solitary* Blue Mud Dauber wasps, Chalybion californicum .  Here's my blog post about *them*:


The ones congregating are overwhelmingly, if not entirely, males.  Male wasps do not sting.  They are looking for a place to bed down for the night, during inclement weather, etc.

Even the females, though they can sting, won't do so unless you physically grab one.  Good luck with that, they are agile and so alert that they are nearly impossible to approach.

Bottom line:  This behavior does not represent any threat whatsoever.  You can use the phenomenon to teach the grandchildren about awe-inspiring natural history, and that simply respecting insects and leaving them alone is the way to deal with most intimidating behavior like this.

Hope this eases your mind.  Blue Mud Daubers kill spiders as food for their young, and they are often specialists on black widows.


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.

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.

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