Self-fertilization
Guides
Icerya
Cushion Scale Insects
Icerya is a genus of scale insects in the family Monophlebidae, notable for containing some of the few hermaphroditic insects known to science. The genus includes approximately 50 described species distributed worldwide, with several species being significant agricultural pests. The most economically important species is Icerya purchasi (cottony cushion scale), native to Australia but now cosmopolitan in distribution, which has caused severe damage to citrus crops globally. Several Icerya species exhibit androdioecy—a rare mating system where hermaphrodites and males coexist—with hermaphrodites possessing ovotestes and reproducing primarily through self-fertilization. This reproductive strategy, combined with the sessile nature of adult females, contributes to their invasive potential. The genus is named after physician-naturalist Dr. Edmond Icery of British Mauritius.