5.10.2. Hermaphroditism


Several of the species of Icerya (Hemiptera: Margarodidae) that have been studied cytologically are gynomonoecious hermaphrodites, as they are female-like but possess an ovotestis (a gonad that is part testis, part ovary). In these species, occasional males arise from unfertilized eggs and are apparently functional, but normally self-fertilization is assured by production of male gametes prior to female gametes in the body of one individual (protandry of the hermaphrodite).

Without doubt, hermaphroditism greatly assists the spread of the pestiferous cottony-cushion scale, I. purchasi (Box 16.2), as single nymphs of this and other hermaphroditic Icerya species can initiate new infestations if dispersed or accidentally transported to new plants. Furthermore, all iceryine margarodids are arrhenotokous, with unfertilized eggs developing into males and fertilized eggs into females.

Chapter 5