Mealybugs are insects in the family Pseudococcidae, unarmored scale insects found in moist, warm habitats. Of the more than 2000 described species, many are considered pests as they feed on plant juices of greenhouse plants, house plants and subtropical trees and also act as a vector for several plant diseases. Some ants live in symbiotic relationships with them, protecting them from predators and feeding off the honeydew which they excrete.
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.
Icerya is a genus of scale insects in the family Monophlebidae. It is named after physician-naturalist Dr. Edmond Icery of British Mauritius.
Aspidiotus is a genus of armoured scale insects. It includes several agricultural and horticultural pests.
Aleyrodinae is a subfamily of whiteflies in the family Aleyrodidae.
Aulacaspis, is a scale insect genus in the family Diaspididae. The type species is Aulacaspis rosae.
Chionaspis is a genus of scale insect. In 2011 geographical sampling and analysis indicated a number of unnamed species in the genus Chionaspis.
Pseudaulacaspis is a genus of scales and mealybugs in the family Diaspididae. There are at least 60 described species in Pseudaulacaspis.
Hemiberlesia is a genus of scales and mealybugs in the family Diaspididae. There are at least 30 described species in Hemiberlesia.
Parlatoria is a genus of scales and mealybugs in the family Diaspididae. There are at least 60 described species in Parlatoria.
Diaspis is a genus of scales and mealybugs in the family Diaspididae. There are at least 50 described species in Diaspis.
Physokermes are a genus of scale insects known as the bud scales. They are restricted to the Holarctic, though Physokermes hemicryphus has been introduced to North America. Some species are plant pests.
Antecerococcus is a genus of scale insects. They are found worldwide but with greater abundance in the Old World. There are about 56 species:
Paracoccus is a genus of true bugs belonging to the family Pseudococcidae.
