Cockerell (Ann. Mag. Nat. Hist., Ser. 7, 13:33-42,1904) named Triepeolus mesillae on the basis of a series of specimens which he collected at Mesilla, New Mexico. A second locality for the species was added by Rozen (Amer. Mus. Novitates 2244, 1966) when he described the larva of T. mesillae from cells of Nomia (Epinomia) triangulifera Vacha! excavated by E. A.
Bouseman, John K.
"Triepeolus Mesillae (Hymenoptera: Apoidea) in Illinois: A Cleptoparasitic Bee New to the Eastern United States,"
The Great Lakes Entomologist: Vol. 15
, Article 11.
Available at: http://scholar.valpo.edu/tgle/vol15/iss2/11