Nur, U. 1977 Electrophoretic comparison of enzymes of sexual and parthenogenetic mealybugs (Homoptera: Coccoidea: Pseudococcidae).. Bulletin of the Virginia Polytechnic Institute and State University Research Division 127: 69-84.

Notes: Pseudococcus obscurus, Ferrisia virgata and Phenacoccus solani; comparison between Pseudococcus and Planococcus species; morphologically similar species were found to differ greatly.