Miller, D.R., & McKenzie, H.L. 1971 Sixth taxonomic study of North American mealybugs, with additional species from South America (Homoptera: Coccoidea: Pseudococcidae).. Hilgardia 40: 565-602.

Notes: Prorhizoecus new gen.; 15 new spp.; distribution; revised keys to North American species and some genera; key to two species of Mammicoccus.