Icerya

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, I. purchasi, are known to be hermaphrodites that reproduce by self-fertilising. Occasionally males are produced from unfertilised eggs, but generally individuals are monoecious with a female-like nature but possessing an ovotestis (a part-testis, part-ovary organ) and sperm is transmitted ovarially from the female to her young. The existence of both hermaphrodites and males in a species is known as androdioecy. 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. ==List of species==

• Icerya aegyptiaca (Douglas 1890). • Icerya albolutea Cockerell 1898. • Icerya bimaculata De Lotto 1959. • Icerya brachystegiae Hall 1940. • Icerya brasiliensis Hempel 1920. • Icerya callitri (Froggatt 1921). • Icerya chilensis Hempel 1920. • Icerya colimensis Cockerell 1902. • Icerya flava Hempel 1920. • Icerya flocculosa Hempel 1932. • Icerya formicarum Newstead 1897. • Icerya genistae Hempel 1912. • Icerya hanoiensis Jashenko & Danzig 1992. • Icerya imperatae Rao 1951. • Icerya insulans Hempel 1923. • Icerya koebelei Maskell 1892. • Icerya leuderwaldti Hempel 1918. • Icerya littoralis mimosae Cockerell 1902. • Icerya littoralis tonilensis Cockerell 1902. • Icerya littoralis Cockerell 1898. • Icerya longisetosa Newstead 1911. • Icerya maxima Newstead 1915. • Icerya maynei Vayssiere 1926. • Icerya menoni Rao 1951. • Icerya minima Morrison 1919. • Icerya minor Green 1908. • Icerya montserratensis Riley & Howard 1890. • Icerya morrisoni Rao 1951. • Icerya nigroareolata Newstead 1917. • Icerya palmeri Riley & Howard 1890. • Icerya paulista Hempel 1920. • Icerya pilosa Green 1896. • Icerya pulchra (Leonardi 1907). • Icerya purchasi citriperda Hempel 1920. • Icerya purchasi crawii Cockerell 1897. • Icerya purchasi maskelli Cockerell 1897. • Icerya purchasi Maskell 1878 - cottony cushion scale • Icerya rileyi Cockerell 1896. • Icerya schoutedeni Vayssiere 1926. • Icerya schrottkyi Hempel 1900. • Icerya seychellarum (type) (Westwood 1855). • Icerya seychellarum cristata Newstead 1909. • Icerya similis Morrison 1923. • Icerya splendida Lindinger 1913. • Icerya subandina Leonardi 1911. • Icerya sulfurea pattersoni Newstead 1917. • Icerya sulfurea Lindinger 1913. • Icerya sumatrana Rao 1951. • Icerya taunayi Hempel 1920. • Icerya travancorensis Rao 1951. • Icerya tremae Vayssiere 1926. • Icerya zeteki Cockerell 1914. • Icerya zimmermani Green 1932. ==References==