Takagi, S. 1990c 1.1.2.6 Polymorphism.. Armored Scale Insects, Their Biology, Natural Enemies and Control [Series title: World Crop Pests, Vol. 4A]. Elsevier Amsterdam, The Netherlands 384 pp.

Notes: This section reviews the literature on the value of polymorphism. Host plants, and site-caused polymorphism is also discussed. Species mentioned include Aspidiotus ancylus, Chionaspis sylvatica, Fiorinia hymenanthis, F. nachiensis, F. odaiensis, Lepidosaphes conchiformis and Phenacaspis nyssae.