Extension > Garden > Diagnose a problem > What insect is this? > General/curiosity insects > Insects with obvious wings: ¾ - 1 inch long >Blue mud dauber
Blue mud dauber
Chalybion californicum
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Jeff Hahn, University of Minnesota Extension
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Joseph Berger, Bugwood.org
Description: 3/4 - 1 inch long. Black with just a little iridescence.
Where/When: Constructs its nests in cavities in plant stems and in buildings. Carries water to a source of soil near its nest to moisten it so it can use the mud to build its nest; found June through August.
Significance: Not aggressive, stings are rare. Does not harm buildings where they build their nests.
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