
Adelges is a genus of insects which feed on conifers. Excepting galls formed by the spruce gall midge, galls are caused by aphid-like insects of the superfamily Phylloxeroidea commonly known as the spruce gall adelgids. They have complex life cycles, some species feeding exclusively on spruce, others feeding on spruce and an alternate conifer. However, galls characteristic of each species are formed only on spruce. Six generations are usually needed to complete the 2-year cycle, and in the case of species having an alternate host, winged adults about 2 mm long are formed only in the generations that move from one host to the other.

Aleurocanthus is a genus of whiteflies in the family Aleyrodidae.

Aonidiella is a genus of scale insects in the family Diaspididae, the armored scale insects. Several species are pests of citrus.

Aphis is a genus of insects in the family Aphididae containing at least 600 species of aphids. It includes many notorious agricultural pests, such as the soybean aphid Aphis glycines. Many species of Aphis, such as A. coreopsidis and A. fabae, are myrmecophiles, forming close associations with ants.

Apiomorpha is a genus of scale insect that induces galls on species of Eucalyptus. Galls are initiated by first-instar nymphs (crawlers) on new plant growth and, when mature, the galls exhibit marked sexual dimorphism. Those induced by females are among the largest and most spectacular of arthropod-induced galls whereas those of males are small and most are tubular. Apiomorpha is known only from Australia and New Guinea although its host, Eucalyptus, has a wider distribution into Indonesia as well.

Aspidiotus is a genus of armoured scale insects. It includes several agricultural and horticultural pests.

Aulacaspis, is a scale insect genus in the family Diaspididae. The type species is Aulacaspis rosae.

Brachycaudus is a genus of aphids of the family Aphididae.

Brevicoryne is a genus of aphid insect that contains many species which are agricultural pests.

Capitophorus is a genus of aphids in the family Aphididae. There are more than 30 described species in Capitophorus.

Ceroplastes is a genus of wax scales in the family Coccidae. There are more than 130 described species in Ceroplastes.

Cinara, the conifer aphids or giant conifer aphids, is a genus of aphids in the family Aphididae. They are widespread in the Northern Hemisphere.

Coccus is a genus of scale insects in the family Coccidae. Several species, such as Coccus viridis, a major pest of coffee, are major agricultural pests. The type species is Coccus hesperidum Linnaeus.

Cryptococcus is a genus of scale insects in the family Eriococcidae.

Cylindrococcus is a genus of scale insects that induces galls on plants of the genus Allocasuarina. There are two described species of Cylindrococcus, both of which occur only in Australia. The galls of adult females look somewhat similar to the cone-like "fruit" of the host plant and might be mistaken for such.

Dactylopius is a genus of insect in the superfamily Coccoidea, the scale insects. It is the only genus in the family Dactylopiidae. These insects are known commonly as cochineals, a name that also specifically refers to the best-known species, the cochineal. The cochineal is an insect of economic and historical importance as a main source of the red dye carmine. It has reportedly been used for this purpose in the Americas since the 10th century. Genus Dactylopius is also important because several species have been used as agents of biological pest control, and because several are known as invasive species.

Dysmicoccus is a genus of scales and mealybugs in the family Pseudococcidae. There are at least 110 described species in Dysmicoccus.

Electromyrmococcus is an extinct genus of mealybug in the Pseudococcidae subfamily Rhizoecinae. The genus currently contains three species, all from the early Miocene, Burdigalian stage, Dominican amber deposits on the island of Hispaniola.

Fioriniina is a subtribe of armored scale insects.

Grylloprociphilus is a genus of woolly and gall-making aphids in the family Aphididae. There is at least one described species in Grylloprociphilus, G. imbricator.

Hyadaphis is a genus of aphids in the family Aphididae. There are about 19 described species in Hyadaphis.

Hyperomyzus is a genus of aphids in the family Aphididae. There are more than 20 described species in Hyperomyzus.

Icerya is a genus of scale insects in the family Monophlebidae. It is named after physician-naturalist Dr. Edmond Icery of British Mauritius.

Kermes is a genus of scale insects in the order Hemiptera. They feed on the sap of evergreen oaks; the females produce a red dye, also called "kermes", that is the source of natural crimson. The word "kermes" is derived from Persian or Turkish qirmiz or kirmizi, "crimson".

Lachnodius is a genus of eriococcid scales, or felt scale insects, in the family Eriococcidae. There are at least 10 described species in Lachnodius, found in Australia.

Lachnus is a genus of aphids and the name-bearing type genus of the subfamily Lachninae. It consists of about 20 species.

Lepidosaphes is a genus of scales and mealybugs in the family Diaspididae. There are at least 150 described species in Lepidosaphes.

Lipaphis is a genus of aphids of the family Aphididae.

Longistigma is a genus of giant aphids in the family Aphididae. There are at least three described species in Longistigma.

Macrosiphoniella is a genus of Aphids of the family Aphididae. The genus was described by Giacomo del Guercio in 1911. There are at least 150 described species in Macrosiphoniella.

Macrosiphum is a genus of aphid. During the summer populations are made of parthenogenetic females. In the fall, males and females are produced; they mate and females lay eggs that overwinter. There are 140 spp. in 3 subgenera.

Megoura is a genus of aphid.

Melaphis rhois is an aphid species first identified by Asa Fitch in 1866. Known as the staghorn sumac aphid, it is the only species in the genus Melaphis. It is a type of woolly aphid and one of the few aphids that induce the formation of galls.

Neotoxoptera, is a genus of aphid in the superfamily Aphidoidea in the order Hemiptera. It is a true bug and sucks sap from plants.

Parasaissetia is a genus of scales and mealybugs in the family Coccidae. There are about five described species in Parasaissetia.

Parlatoria is a genus of scales and mealybugs in the family Diaspididae. There are at least 60 described species in Parlatoria.

Periphyllus is a genus of maple aphids in the family Aphididae. There are more than 40 described species in Periphyllus.

Phenacoccus is a genus of mealybugs in the family Pseudococcidae. There are at least 180 described species in Phenacoccus.

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.

Pinnaspis, first described by Theodore Dru Alison Cockerell in 1892, is a genus of scale insects belonging to the family Diaspididae, or armored scale insects. There are currently 42 species within the genus Pinnaspis.
The scale insect genus Porphyrophora is a large group in the family Margarodidae, which includes the insects Polish cochineal and Armenian cochineal formerly used in dye production.

Prociphilus is an aphid genus of the subfamily Eriosomatinae, which cause the plants they attack to produce galls. The aphids reside and feed within the gall.

Pseudaulacaspis is a genus of scales and mealybugs in the family Diaspididae. There are at least 60 described species in Pseudaulacaspis.

Pseudococcus is a genus of unarmoured scale insects in the family Pseudococcidae, the mealy bugs. There are more than 150 species of Pseudococcus.

Pulvinaria is a scale insect genus in the family Coccidae. The type species is Coccus vitis Linnaeus.

Rhopalosiphum is a genus of aphid of the family Aphididae that includes 16 species worldwide. Apart from sucking the phloem of host plants and thereby being treated in agriculture as pests, some species are vectors for viral pathogens.

Siphoninus is a genus of whiteflies in the family Aleyrodidae.
Sitobion is a genus of aphids in the family Aphididae. There are more than 80 described species in Sitobion.
Tetraneura is a genus of woolly and gall-making aphids in the family Aphididae. There are at least 30 described species in Tetraneura.

Tinocallis is a genus of aphids in the subfamily Calaphidinae.

Toumeyella is a genus of tortoise scales in the subfamily Myzolecaniinae of the true bug family Coccidae.

Tuberolachnus salignus, or the giant willow aphid, is a species of aphid, in the genus Tuberolachnus. They are reputed to be the largest aphids, with a body length of up to 5.8mm.

Uroleucon is a genus of aphids in the family Aphididae. Most species feed on Asteraceae.