A chemical method of determining the amount of blood ingested by mosquitoes was used to test the claim of Adlakha and Pillai (1976) that insemination is involved in the regulation of blood meal size. Inseminated and uninseminated Aedes aegypti do not differ in the amount of blood ingested. The data show that if excretion before, during, and after feeding, is not accounted for, unacceptable errors are introduced in blood meal size determinations. © 1979.