Scale insects are small insects of the order Hemiptera, suborder Sternorrhyncha. Of dramatically variable appearance and extreme sexual dimorphism, they comprise the infraorder Coccomorpha which is considered a more convenient grouping than the superfamily Coccoidea due to taxonomic uncertainties. Adult females typically have soft bodies and no limbs, and are concealed underneath domed scales, extruding quantities of wax for protection. Some species are hermaphroditic, with a combined ovotestis instead of separate ovaries and testes. Males, in the species where they occur, have legs and sometimes wings, and resemble small flies. Scale insects are herbivores, piercing plant tissues with their mouthparts and remaining in one place, feeding on sap. The excess fluid they imbibe is secreted as honeydew on which sooty mold tends to grow. The insects often have a mutualistic relationship with ants, which feed on the honeydew and protect them from predators. There are about 8,000 described species.
Diaspididae is the largest family of scale insects with over 2650 described species in around 400 genera. As with all scale insects, the female produces a waxy protective scale beneath which it feeds on its host plant. Diaspidid scales are far more substantial than those of most other families, incorporating the exuviae from the first two nymphal instars and sometimes faecal matter and fragments of the host plant. These can be complex and extremely waterproof structures rather resembling a suit of armor. For this reason these insects are commonly referred to as armored scale insects. As it is so robust and firmly attached to the host plant, the scale often persists long after the insect has died.
Diaspidinae is the largest subfamily of Diaspididae, with more than 200 genera in two tribes.
Aulacaspis, is a scale insect genus in the family Diaspididae. The type species is Aulacaspis rosae.
Leucaspidini is a tribe of armored scale insects.
Parlatoriini is a tribe of armored scale insects. Takagi (2002) indicated that the Parlatoriini appear to be phylogenetically related to the Smilacicola and the Odonaspidini. Takagi went on to say about the tropical east Asian Parlatoriini that, The current classification of their genera may be largely tentative because the adult females are simple-featured and much modified owing to the pupillarial mode of life, and also because the second instar nymphs are generally similar among parlatoriines, whether the adult females are pupillarial or not. Andersen found that separating out pupillarial forms into a separate subtribe, Gymnaspidina, was counterproductive, as being non-dispositive.
Aonidiini is a tribe of armored scale insects in the family Diaspididae.
Smilacicolini is a tribe of armored scale insects.
Diaspidini is a tribe in the armored scale insect family Diaspididae. The insects are highly invasive, and are significant economic pests found worldwide.
Lepidosaphidini is a tribe of armored scale insects.
Furcaspidina is a subtribe of armored scale insects, traditionally regarded as part of the Aspidiotini. While the subtribe Furcaspidina was not mentioned in Takagi's 2002 study, the Aspidiotini were not deemed as problematical as the Diaspidini and Lepidosaphidini. In 2006, Williams reduced the Furcaspidina to a single genus, with about twenty-eight species. Andersen in 2009 suggested that the Furcaspidina belonged in an expanded subfamily of Diaspidinae; however, additional analysis suggests that the furcaspids are better placed in a distinct, but laterally equivalent subfamily to the Diaspidinae, possibly together with the gymnaspids which Borchsenius placed in the Aspidiotinae subfamily.
Gymnaspidina is a subtribe of armored scale insects. Takagi (2002) does not mention the Gymnaspidina, but in 2006 Morse and Normark still placed Gymnaspis aechmeae within the Parlatoriini tribe. Anderson (2010) found Gymnaspidina to be radically polyphyletic and suggested that the gymnaspids and the furcaspids might be placed in a distinct, but laterally equivalent subfamily to the Diaspidinae, rather than in the Aspidiotinae.
Parlatoriina is a subtribe of armored scale insects.
Chionaspidina is a subtribe of armored scale insects established by Borchenius. But unlike many of the subtribes recognized by Borchenius, this one was found to be morphologically valid by Takagi. Similarly, in molecular analysis, Andersen et al. found a clade roughly corresponding to the subtribe Chionaspidina.
Fioriniina is a subtribe of armored scale insects in the family Diaspididae. They are found almost exclusively in the Old World.
Rugaspidiotina is an obsolete subtribe of armored scale insects. It was established by Balachowsky in 1949 to accept those Diaspidinae which had rugaspidiotine characteristics as exemplified by genus Rugaspidiotus MacGillivray, species Rugaspidiotus arizonicus, and was moved from the Odonaspidini to the Diaspidini by Borchsenius. It was raised to tribe status as Rugaspidiotini. However, close examination of species assigned to the Rugaspidiotini showed that the rugaspidiotine characteristics convergently evolved in different groups of diaspidids. Rugaspidiotini and Rugaspidiotina are now regarded as obsolete groupings.
Chionaspis is a genus of scale insect. In 2011 geographical sampling and analysis indicated a number of unnamed species in the genus Chionaspis.
Fiorinia is a genus of armored scale insects with around 70 species. The species are widely distributed around the world. However, the large majority of them are found in southern Asia. They infest woody plants like forest or crop trees, palm trees and shrubs. Several species are invasive and these are mainly polyphagous species which have spread with the trade of ornamentals. For example, 7 species have been introduced into North America.
Lepidosaphes is a genus of armored scale insects in the family Diaspididae. There are at least 150 described species in Lepidosaphes, found worldwide.
