Hermaphroditism is extremely rare in the insect world despite the comparatively common nature of this condition in the crustaceans. Several species of Icerya, including the pestiferous cottony-cushion scale, Icerya purchasi, are known to be hermaphrodites that reproduce by self-fertilising. Occasionally reproductively functioning males are produced from unfertilised eggs but generally individuals are monoecious and with a female-like nature but possessing an ovotestis which is part testis part ovary and sperm is transmitted ovarially from the female to her young. This hermaphroditic sexual self-sufficiency where a single individual can populate new territory has contributed to the invasive spread of the cottony-cushion scale insect away from its native Australia.
