Trigonaspis cupella Phylloteras cupella, formerly Trigonaspis cupella, also known as the urn gall wasp or the banded urn gall wasp, is a species of cynipid wasp that induces leaf galls on a number of oak species in western North America.

[1][2] Host species include Arizona white, blue, Engelmann, gray, leather, netleaf, scrub, and shrub oaks.

[1] In the United States, galls induced by this species of wasp have been documented in California, Arizona, and New Mexico.

[3] The galls usually have an ombré gradient: lighter at the top, and darker toward the bottom.

[1] The wasp measures 1.3–2 millimeters in length.