Plant-parasite
Guides
Acalitus
Acalitus is a genus of microscopic eriophyoid mites in the family Eriophyidae. Species within this genus are cosmopolitan plant parasites that induce gall formation on various host plants. Several species are significant agricultural pests, including Acalitus essigi and Acalitus vaccinii, which affect berry crops, and Acalitus phloeocoptes, which damages stone fruit trees. The genus exhibits narrow host specificity, with individual species typically restricted to particular plant genera or families.
Acalitus ruelliae
Acalitus ruelliae is a species of gall mite in the family Eriophyidae. This microscopic arachnid induces abnormal plant growths (galls) on its host plants. The species epithet indicates an association with plants in the genus Ruellia (Acanthaceae). Like other eriophyid mites, it is highly host-specific.
Aceria baccharices
Mule Fat Blister Mite, mulefat leaf-blister mite
Aceria baccharices is an eriophyid mite species native to North America that induces distinctive leaf galls on two host plants in the genus Baccharis. First described by Hartford H. Keifer in 1945, this microscopic arachnid creates warty, protruding galls on leaf surfaces that serve as protected nurseries for developing mite populations. The species exhibits strong host specificity, with populations in northern California associated primarily with Baccharis salicifolia and southern populations utilizing Baccharis glutinosa. Adults eventually exit the galls through anterior holes, which may remain visible on the leaf surface.
Aceria baccharipha
Baccharis Leaf Blister Mite
Aceria baccharipha, known as the Baccharis Leaf Blister Mite, is an eriophyid mite in the family Eriophyidae. Like other members of the superfamily Eriophyoidea, it is a worm-like, four-legged mite that parasitizes plants. The species is associated with Baccharis plants, where it causes leaf blistering damage. Eriophyid mites represent one of the largest adaptive radiations of plant-parasitic arthropods, with most species specializing on specific host plants.
Aceria brachytarsus
pouch gall mite, walnut purse gall mite
Aceria brachytarsus is an eriophyoid mite species that induces leaf-pouch galls on walnut trees (Juglans spp.). Formerly classified as Eriophyes brachytarsus, this microscopic arachnid is known for producing distinctive bladder-like galls on foliage. The species has been documented in California, Iran, Spain, and Belgium.
Aceria campestricola
Elm Leaf Gall Mite
Aceria campestricola is a gall-forming eriophyid mite that induces small pouch-like galls on elm leaves. First described in 1865, this microscopic arachnid overwinters in bark crevices before emerging in spring to attack new foliage. The species exhibits complex taxonomic history with related forms previously described under separate names based on gall morphology.
Aceria caulis
Black Walnut Petiole Gall Mite
Aceria caulis, the Black Walnut Petiole Gall Mite, is an eriophyid mite in the superfamily Eriophyoidea. Like other members of its genus, this species is a plant parasite that induces abnormal plant growth. The specific epithet 'caulis' and common name suggest association with walnut petioles, though detailed biological studies of this particular species appear limited in the available literature.
Aceria celtis
Witches' Broom Mite
Aceria celtis is an eriophyid mite in the family Eriophyidae that infests hackberry trees (Celtis spp.). The species is commonly known as the Witches' Broom Mite due to the distinctive gall-like growths it induces on host plants. Like other eriophyid mites, it is microscopic (approximately 0.2 mm), worm-shaped, and possesses only four legs. The mite is a specialized plant parasite with a narrow host range centered on Celtis species.
Aceria cephalanthi
Buttonbush Mite
Aceria cephalanthi, commonly known as the Buttonbush Mite, is an eriophyid mite in the genus Aceria. Eriophyid mites are minute, worm-like arachnids with four legs that are specialized plant parasites. Members of this genus typically infest specific host plants, with this species associated with buttonbush (Cephalanthus). Like other eriophyids, it likely has a short development period and lives in protected areas of the plant.
Aceria cinereae
butternut erineum mite
Aceria cinereae, the butternut erineum mite, is an eriophyid mite in the family Eriophyidae. Eriophyid mites are worm-like, four-legged plant parasites that are among the smallest arthropods, with some species measuring less than 0.1 mm. The genus Aceria contains many species that specialize on specific host plants, often causing distinctive growth abnormalities. A. cinereae has been observed 457 times according to iNaturalist records.
Aceria dina
Tupelo leaf edge gall mite
Aceria dina is a gall-forming mite in the family Eriophyidae, commonly known as the tupelo leaf edge gall mite. This species induces distinctive gall structures on the leaf edges of its host plant, Nyssa sylvatica (black tupelo or sour gum). Like other eriophyid mites, it has a worm-like, elongated body with four legs and measures approximately 0.2 mm in length. The mite is an obligate plant parasite with a highly specialized relationship to its host.
Aceria elongata
Crimson Erineum Mite
Aceria elongata, commonly known as the crimson erineum mite, is an eriophyid mite that induces distinctive erineum galls on the upper leaf surfaces of sugar maple (Acer saccharum). The galls progress from pale greenish patches to rich red-purple coloration as the season advances. This microscopic, worm-like mite has two alternating generations per year and is known from the eastern coast of the United States and Canada. At high densities, it can cause leaf distortion and premature leaf drop, though damage is generally not severe enough to require control measures.
Aceria negundi
box elder pouch gall mite
Aceria negundi, commonly known as the box elder pouch gall mite, is an eriophyid mite that specializes on box elder (Acer negundo). This microscopic arachnid induces characteristic pouch galls on its host plant. Like other members of the Eriophyidae, it has a worm-like body with four legs and is among the smallest plant-parasitic mites, measuring less than 0.2 mm in length. The species has been observed across a broad geographic range with over 4,700 documented observations.
Aceria nyssae
Black Tupelo Gall Mite
Aceria nyssae is an eriophyid gall mite that induces distinctive leaf curl galls on Nyssa sylvatica (black tupelo, sour gum). The mite's feeding activity causes leaf margins to curl inward, forming hollow pockets that shelter the mites and their eggs. This species exemplifies the highly specialized host relationships typical of Eriophyoidea, where individual species are often restricted to a single plant host genus. The galls are most evident on young leaves at branch tips during the growing season. Like other eriophyid mites, A. nyssae is extremely small and difficult to observe directly, with populations typically assessed through gall symptoms rather than mite counts.
Aceria parulmi
Elm Finger Gall Mite
Aceria parulmi is an eriophyid mite species commonly known as the Elm Finger Gall Mite. It is a plant-parasitic mite that induces distinctive gall-like structures on elm leaves. Like other members of the genus Aceria, it has a worm-like, elongated body with four legs and is extremely small, typically less than 0.2 mm in length. The mite is specialized to feed on elm species (Ulmus), causing characteristic finger-shaped galls on leaf surfaces.
Aceria theospyri
persimmon leaf blister gall
Aceria theospyri is a gall-forming eriophyid mite that produces distinctive leaf blister galls on persimmon (Diospyros virginiana). As a member of the superfamily Eriophyoidea, this microscopic mite has a worm-like, elongated body with only four legs. The species is highly host-specific, feeding exclusively on persimmon and causing characteristic blister-like deformities on leaves. Like other eriophyid mites, it has a short development period allowing rapid population buildup. The mite represents one of thousands of specialized plant-parasitic mites in this ancient lineage that radiated over 200 million years ago.
Aceria trichophila
Aceria trichophila is a species of eriophyid mite in the family Eriophyidae. Eriophyid mites are minute, worm-like plant parasites characterized by their elongated bodies and reduced leg number. Like other members of the genus Aceria, this species is likely specialized on a specific host plant or narrow group of related plants, reflecting the highly host-specific nature of Eriophyoidea. The species has been documented through iNaturalist observations but detailed biological information appears limited in published sources.
Aceria trinema
Aceria trinema is a species of eriophyid mite in the family Eriophyidae. Like other members of the genus Aceria, it is a minute, worm-like mite with a highly reduced body plan adapted for living in confined spaces on plants. Eriophyid mites are among the smallest arthropods, with some species measuring less than 0.1 mm in length. The genus Aceria contains numerous species that are specialized plant parasites, many of which cause distinctive damage symptoms including galls, leaf curling, and witches' brooms on their host plants.
Aceria triplacis
Aceria triplacis is a species of eriophyid mite in the genus Aceria, family Eriophyidae. Like other members of the superfamily Eriophyoidea, it is a minute, worm-like, four-legged mite. Eriophyid mites represent one of the largest lineages of plant-parasitic arthropods, with conservative estimates of 100,000 living species. Most species in this group are highly specialized parasites of vascular plants, typically associated with specific host species or genera. The specific host associations and biology of A. triplacis have not been documented in published literature.
Aceria vaga
Aceria vaga is a species of eriophyid mite in the family Eriophyidae. Eriophyid mites are minute, worm-like arachnids with four legs that are specialized plant parasites. Many species in this group cause distinctive growth abnormalities on their host plants, including galls, witches' brooms, and leaf distortions. Aceria vaga is among the numerous eriophyid species that remain poorly studied despite the group's significant agricultural and ecological importance.
Aculus minutissimus
Aculus minutissimus is a minute eriophyid mite, commonly known as a gall mite or rust mite. It is among the smallest arthropods, with a worm-like body and only two pairs of legs in the adult stage. Species in this genus are frequently associated with specific host plants, though detailed host records for A. minutissimus remain limited. The mite is known from numerous observations, suggesting it is relatively widespread but easily overlooked due to its microscopic size.
Asphondylia pseudorosa
Asphondylia pseudorosa is a gall midge species in the family Cecidomyiidae, described by Dorchin in 2015. Like other members of the genus Asphondylia, it is presumed to be a gall-inducing insect that manipulates plant tissue to form protective structures for its developing larvae. The specific host plant associations and gall morphology for this particular species remain poorly documented in the available literature.
Callirhytis rugulosa
Callirhytis rugulosa is a species of gall wasp in the family Cynipidae. Like other members of this family, it induces the formation of galls on host plants, though specific gall morphology and host associations for this species are not well documented in available sources. The species belongs to a genus predominantly associated with oak galls.
Caryomyia asteris
Hickory Starburst Gall Midge
Caryomyia asteris is a gall midge species in the family Cecidomyiidae, described by Raymond Gagné in 2008. It is known by the common name "Hickory Starburst Gall Midge" and induces distinctive gall formations on hickory trees (Carya spp.). The species is part of a genus specialized in creating galls on hickory and pecan hosts.
Colopha
Colopha is a genus of gall-forming aphids in the family Aphididae, first described by Monell in 1877. Species in this genus induce distinctive galls on host plants, most notably the elm cockscomb gall on American elm. The genus exhibits complex life cycles involving host alternation between woody plants and grasses, with both bisexual and unisexual reproductive strategies documented across species.
Dasineura
Dasineura is a genus of gall midges in the family Cecidomyiidae. Species in this genus are known for inducing galls on various host plants, including woody shrubs and trees. Some species are significant agricultural pests, such as Dasineura jujubifolia on jujube, which can reduce yields by at least 20%. The genus exhibits diverse gall morphologies, from simple leaf galls to complex flower-like structures formed by developmental reprogramming of host tissues.
Dasineura crataegibedeguar
hawthorn button-top gall midge
Dasineura crataegibedeguar is a gall midge in the family Cecidomyiidae that induces distinctive galls on hawthorns (Crataegus spp.). The species is known for forming button-top or bedeguar-like galls on host plant tissues. Like other Dasineura species, it has a complex life cycle involving gall induction and larval development within plant tissue. The species was originally described by Osten Sacken in 1878 and has undergone taxonomic revision, with some authorities placing it in the genus Blaesodiplosis.
Dasineurini
Dasineurini is a tribe of gall midges (Cecidomyiidae) containing numerous species that induce galls on plants. Members are small, delicate flies whose larvae develop within plant tissues, causing characteristic growth deformities. The tribe includes economically significant pests such as those affecting wheat and other crops.
Eriophyes betulae
Birch gall mite
Eriophyes betulae is a gall-forming eriophyid mite that induces characteristic galls on birch trees (Betula species). The mite is microscopic, worm-like in body form with only two pairs of legs—diagnostic features of the Eriophyidae family. It has been documented in Denmark and other parts of Europe. Like other eriophyid mites, it feeds on plant tissues and manipulates host growth to create sheltered feeding structures.
Kokkocynips rileyi
Kokkocynips rileyi is a species of gall wasp in the family Cynipidae. The species was originally described as Andricus rileyi by Ashmead in 1896 and has undergone taxonomic revisions, with recent treatments placing it in the genus Kokkocynips. Like other cynipid wasps, this species induces gall formation on host plants, though specific gall morphology and host associations require further documentation. The species name honors an individual, following the Latin convention for male eponyms ending in -i.
Lasioptera ephedrae
Mormon Tea Stem Gall Midge
Lasioptera ephedrae is a species of gall midge in the family Cecidomyiidae. It is known for inducing stem galls on Ephedra trifurca, a desert shrub commonly called Mormon tea. The species was described by Cockerell in 1898 and is found in arid regions of the southwestern United States and adjacent Mexico. Like other gall midges, it has a complex life cycle involving intimate association with its host plant.
Neolasioptera clematidis
Neolasioptera clematidis is a gall midge species in the family Cecidomyiidae, first described by Felt in 1907. The specific epithet 'clematidis' suggests an association with plants in the genus Clematis. As with other gall midges, this species likely induces gall formation on host plants.
Phylloxera myristica
Phylloxera myristica is a gall-forming insect in the family Phylloxeridae, closely related to aphids. Like other phylloxerans, this species induces abnormal plant growths (galls) on host plants through chemical secretions that manipulate plant development. The insect develops within these protective structures, which provide both shelter and nutrition. Specific host associations and detailed biology for this species remain poorly documented in available literature.
Phylloxera picta
Phylloxera picta is a species of gall-forming insect in the family Phylloxeridae, closely related to aphids. Like other phylloxerans, it induces abnormal plant growths (galls) on host trees through chemical secretions that manipulate plant tissue development. The species overwinters as eggs and has a complex life cycle involving multiple generations and both winged and wingless forms.
Phylloxera stoetzelae
Phylloxera stoetzelae is a species of phylloxeran, a group of tiny, soft-bodied, sap-sucking insects closely related to aphids. Members of the genus Phylloxera are known for inducing galls on host plants through chemical secretions that stimulate abnormal plant tissue growth. The species was named in honor of entomologist Mark Stoetzel. Like other phylloxerans, it likely completes a complex life cycle involving both parthenogenetic and sexual reproduction phases, with overwintering eggs hatching in spring to initiate gall formation on new growth.
Phytomyza
Phytomyza is a genus of leaf-mining flies in the family Agromyzidae, comprising at least 170 described species. Larvae develop as miners within living plant leaves, creating distinctive serpentine or blotchy galleries between the upper and lower epidermis. Adults are small, typically black or dark-colored flies resembling tiny houseflies. The genus exhibits high host specificity, with individual species often restricted to particular plant genera or families.
Protobalandricus spectabilis
Tapered Stem Gall Wasp
Protobalandricus spectabilis is a gall wasp species in the family Cynipidae, originally described as Andricus spectabilis by Kinsey in 1922 and later transferred to the genus Protobalandricus by Nicholls, Stone & Melika in 2018. It is commonly known as the Tapered Stem Gall Wasp. The species is part of the diverse Cynipini tribe, which includes numerous gall-inducing wasps associated with oaks and related plants. As a cynipid wasp, it induces the formation of plant galls during its life cycle, though specific gall morphology and host associations for this species require further documentation.
Rhopalomyia
Rhopalomyia is a large genus of gall midges (Cecidomyiidae) comprising at least 220–267 described species with cosmopolitan distribution. Established by Ewald Heinrich Rübsaamen in 1892, most species induce highly specific galls on Asteraceae, though some species have expanded to Fabaceae, Apocynaceae, Ericaceae, and Myrtaceae. Galls occur on diverse plant organs including buds, leaves, stems, rhizomes, and flower heads. The genus exhibits complex host associations and gall polymorphism, with some species serving as biological control agents.
Rhopalomyia floccosa
Sagebrush Woolly Stem Gall Midge
Rhopalomyia floccosa is a gall midge in the family Cecidomyiidae that induces distinctive woolly stem galls on California sagebrush (Artemisia californica). The species produces white, woolly, monothalamous bud galls measuring approximately 5 mm in diameter individually, with coalescing galls reaching 30–40 mm in length. It is a specialist herbivore with a known association limited to this single host plant.
Spanioneura fonscolombii
Spanioneura fonscolombii is a plant-parasitic psyllid specialized on box (Buxus) species. First described from Europe in 1848, it has been accidentally introduced to the United States and represents a pest of ornamental and native boxwoods. The species shows distinctive green coloration with patterned wings and has been documented causing damage to host plants, with some dispute regarding gall formation.
Vasates
eriophyid gall mites
Vasates is a genus of eriophyid mites (family Eriophyidae) that induce gall formation on host plant leaves. Species in this genus are associated with diverse host plants including maple (Acer), black locust (Robinia), and lupine (Lupinus). The genus includes at least three described species: V. aceriscrumena, V. quadripedes, and V. lupini. Males exhibit specialized mate-guarding behavior of quiescent female nymphs prior to their emergence.
Vasates quadripedes
Maple Bladdergall Mite, maple bladder-gall mite
Vasates quadripedes is an eriophyid mite known for inducing distinctive bladder-like galls on maple leaves. The species is native to North America and has been introduced to parts of Europe, including Britain where it was first recorded in 2002. It is associated primarily with silver maple, red maple, and sugar maple. The galls it produces are a reliable indicator of its presence and are more readily observed than the microscopic mites themselves.
Zopheroteras compressum
Zopheroteras compressum is a species of gall wasp in the family Cynipidae, originally described as Acraspis compressus by Gillette in 1891. Like other members of its family, it is an obligate plant parasite that induces gall formation on host plants. The species has been documented through 202 iNaturalist observations, indicating it is not uncommon but remains poorly studied in the scientific literature. As a cynipid wasp, it likely exhibits the typical life history of alternating sexual and asexual generations, though specific details for this species are not well documented.