Phloem-feeders
Guides
Aclerdidae
Aclerdid Scales, Flat Grass Scales
Aclerdidae is a family of scale insects (superfamily Coccoidea) comprising five genera and approximately 58 species. Members are specialized herbivores primarily associated with grasses (Poaceae), where they inhabit leaf sheaths and feed on plant sap. The family exhibits highly derived morphology including leglessness, reduced antennae, and unique anal apparatus. Several species have become economically significant as pests of agricultural and wetland grasses, including the invasive roseau cane scale (Nipponaclerda biwakoensis) in North America and Aclerda takahashii on sugarcane.
Aphalaridae
jumping plant lice, psyllids, lerp insects
Aphalaridae is a family of sap-sucking insects in the superfamily Psylloidea, commonly known as jumping plant lice or psyllids. The family contains approximately 749 species with worldwide distribution except Antarctica. Members are small, phloem-feeding insects, often highly host-specific. The family was revised in 2012 and 2021 to include seven subfamilies based on molecular and morphological data. Several species are significant agricultural and forestry pests, including the red gum lerp psyllid (Glycaspis brimblecombei) and the common pistachio psyllid (Agonoscena pistaciae).
Atheas
lace bugs
Atheas is a genus of lace bugs (Hemiptera: Tingidae) comprising approximately 15 described species. These insects are characterized by their distinctive reticulated, lace-like forewings typical of the family. The genus is primarily associated with wetland and swamp habitats in North America, with Atheas austroriparius being the best-studied species. Members feed on phloem sap from a diverse range of woody host plants using piercing-sucking mouthparts.
Blissidae
Chinch Bugs and Allies
Blissidae is a family of true bugs (Hemiptera) comprising over 400 species in nearly 50 genera. Members are elongate insects, typically four to seven times as long as broad, with many species exhibiting short-winged forms. All species feed on plant sap, primarily from grasses (Poaceae) and sedges (Cyperaceae), with most living between leaf sheaths. The family was elevated from subfamily status within Lygaeidae by Thomas Henry in 1997. Several species are significant agricultural pests, notably Blissus leucopterus (true chinch bug), which damages corn and other cereal crops.
Calaphidinae
Calaphidinae is the second-largest subfamily in the family Aphididae, comprising more than 60 genera and over 360 described species. The subfamily includes aphids primarily associated with woody host plants, particularly birches (Betula), oaks (Quercus), and related tree species in the families Fagaceae and Betulaceae. Recent molecular phylogenetic studies have substantially revised the classification of Calaphidinae, establishing eight tribal divisions and revealing that the group is paraphyletic with respect to the former 'Saltusaphidinae'. The subfamily shows complex evolutionary patterns involving host plant shifts and geographic expansion from an Eastern Palaearctic origin.
Cicadomorpha
Spittlebugs, Cicadas, Leafhoppers and Treehoppers
Cicadomorpha is an infraorder of Hemiptera comprising approximately 35,000 described species worldwide, including cicadas, leafhoppers, treehoppers, and spittlebugs. The group has a fossil record extending to the Late Permian, with extinct families such as Palaeontinidae representing diverse Mesozoic lineages. All members are obligate plant-feeders utilizing specialized mouthparts for sap extraction. Many species produce acoustic signals or substrate vibrations for communication, with sound production mechanisms varying among superfamilies.
Cinara
giant conifer aphids, conifer aphids
Cinara is a genus of aphids comprising approximately 200-243 species, commonly known as giant conifer aphids. These insects are specialized feeders on conifers in the families Pinaceae and Cupressaceae, including pines, firs, spruces, cedars, and cypresses. Molecular studies indicate their tribe Eulachnini represents the basal group for other aphids. Several species are significant pests of cultivated Christmas trees, particularly Fraser fir production in the southeastern United States.
Coccidae
soft scales, wax scales, tortoise scales
Coccidae is a family of scale insects in the superfamily Coccoidea, commonly known as soft scales, wax scales, or tortoise scales. The family contains over 1,100 species in 171 genera worldwide. Females are typically flat with elongated oval bodies and smooth integument often covered with wax; they may possess legs in some genera but not in others. Males may be winged or wingless. Coccidae are distinguished from armored scales (Diaspididae) by their soft, waxy covering rather than a hard, separable scale. Many species are economically important agricultural and horticultural pests.
Diaspididae
Armored Scale Insects, Armored Scales, Hard Scales
Diaspididae is the largest family of scale insects, comprising over 2,650 described species in approximately 400 genera. Members are commonly known as armored scale insects due to their distinctive protective covering, which incorporates exuviae from the first two nymphal instars, sometimes with fecal matter and host plant fragments. The female remains permanently beneath this armor, feeding on host plant tissues through piercing-sucking mouthparts. The family includes numerous economically significant pests such as the California red scale (Aonidiella aurantii), San Jose scale (Diaspidiotus perniciosus), and gloomy scale (Melanaspis tenebricosa), which damage crops, ornamentals, and forest trees worldwide.
Enchenopa
Enchenopa is a genus of treehoppers (family Membracidae) containing more than 50 described species. The genus underwent major revision in 2014, resulting in 51 recognized species. Members are characterized by their enlarged, often ornate pronotum typical of treehoppers. The Enchenopa binotata species complex has been extensively studied as a model system for sympatric speciation through host plant shifts, with different species or populations specialized on distinct host plants and exhibiting assortative mating based on plant-associated vibrational signals.
Eriococcidae
Felt Scales, Eriococcids, Bark Scales
Eriococcidae is a family of scale insects in the order Hemiptera, commonly known as felt scales or eriococcids. As of 2023, the family comprises 109 genera and 681 species. Members are phloem-feeding herbivores typically associated with specific plant hosts. The family is not monophyletic; recent ribosomal DNA research indicates it represents an aggregation of several distinct evolutionary lineages, with morphologically similar species sometimes being distantly related. Many species produce distinctive waxy ovisacs or induce galls on host plants.
Greenideinae
Greenideinae is a subfamily of aphids (Aphididae) comprising approximately 179 extant species across 18 genera in three tribes: Cervaphidini, Greenideini, and Schoutedeniini. Species are primarily distributed in eastern and southern Asia, with many exhibiting specialized associations with woody host plants, particularly in Fagaceae. The subfamily has been extensively studied for its complex symbiotic relationships with microbial associates, including the primary endosymbiont *Buchnera aphidicola* and diverse secondary symbionts.
Liviidae
plant lice, psyllids, jumping plant-lice
Liviidae is a family of plant-parasitic hemipterans commonly known as plant lice or jumping plant-lice. The family comprises more than 20 genera and approximately 370 described species worldwide. Members are characterized by their ability to jump and their association with vascular plants as phloem-feeders. The family includes significant agricultural pests, most notably Diaphorina citri (Asian citrus psyllid), the primary vector of citrus greening disease (Huanglongbing). Liviidae was formerly treated as Triozidae, and recent taxonomic revisions recognize three monophyletic subfamilies: Euphyllurinae, Liviinae, and the monotypic Neophyllurinae.
Psylla
jumping plant lice, psyllids
Psylla is the type genus of the family Psyllidae, comprising small sap-sucking insects commonly known as jumping plant lice or psyllids. The genus contains at least 110 described species, each typically associated with specific host plants. Psylla species are phloem-feeders that use piercing-sucking mouthparts to extract plant sap. While some species in related genera such as Cacopsylla are significant agricultural pests, Psylla itself includes species with more restricted host ranges, including Psylla alni on alders, Psylla betulae on birches, and Psylla buxi on boxwood. The genus is distinguished from similar taxa by morphological features and host associations.
Psyllinae
Psyllinae is a subfamily of plant-parasitic hemipterans within the family Psyllidae, comprising approximately 12 genera and at least 40 described species. Members are commonly known as psyllids or jumping plant lice. The subfamily includes economically significant pest species such as the apple psylla (Cacopsylla mali) and pear psylla (Cacopsylla pyri). Species exhibit biogeographic patterns correlating with altitude and regional flora, with Oriental elements dominating at lower elevations and Himalayan and Australian elements prevalent above 2500 m in montane systems.
Pulvinaria
cottony cushion scales, soft scales
Pulvinaria is a genus of soft scale insects (family Coccidae) characterized by females that produce conspicuous cottony or flocculent wax ovisacs to protect their eggs. The genus includes economically significant agricultural and ornamental pests with broad host ranges spanning numerous woody plant families. Several species have invasive potential and have established beyond their native ranges, including P. aurantii, P. psidii, and P. urbicola. The genus exhibits considerable morphological variability, complicating species identification.
Smiliinae
Smiliinae is a large subfamily of treehoppers (Membracidae) comprising approximately 100 genera organized into 10 tribes, with the majority of diversity concentrated in the Americas. The subfamily includes approximately 140 described species, though this likely underrepresents true diversity. Members are characterized by elaborate pronotal modifications that produce bizarre shapes including thorn-like projections, ant-mimicking forms, and other structures whose functions remain incompletely understood. The nominotypical tribe Smiliini contains 169 species in 23 genera and is predominantly Nearctic in distribution, with evolutionary origins traced to Central America and Mexico followed by multiple dispersals to temperate North America.
Toumeyella
tortoise scales, pine tortoise scales
Toumeyella is a genus of soft scale insects (family Coccidae) commonly known as tortoise scales. These sedentary, sap-feeding insects infest conifers and broadleaf trees, with females protected by a waxy, shell-like covering. Several species are significant forest and ornamental pests, including T. liriodendri (tuliptree scale) and T. pini (striped pine scale). The genus is characterized by phloem-feeding habits, honeydew production, and frequent mutualistic associations with ants.