In revising the genus Triaspis Haliday, as found in North America north of Mexico, the author studied an undescribed species from Mexico. This form is a parasite of Apion godmani Wagner, a weevil of economic importance. This paper provides a name and a description for this new parasite.

The author is most grateful to Dr. V. S. L. Pate of Cornell University for his helpful criticism of the manuscript, and also to Mr. C. F. W. Muesebeck of the U.S. National Museum for the loan of material, and to Dr. Arthur C. Smith of Cornell University for the specimens collected while he was studying the biology of the host in Mexico.