Euura macgillivrayi
Gall: on Salix luteosericea Rydb. [exigua]; a gradual enlargement of the twig about 30 mm. long.
Range: Boulder, Colorado, at the mouth of Boulder Canyon. Adults appearing early in May in the field, earlier in the laboratory (S. A. Rohwer). (Type locality.)
”- SA Rohwer: (1912) The Sawflies of Boulder County, Colorado©
Reference: https://www.biodiversitylibrary.org/page/29650370#page/118/mode/1up