Gall-former
Guides
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 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.
Acericecis
maple gall midges
Acericecis is a genus of gall midges in the family Cecidomyiidae. The genus contains five described species, four extant and one known only from fossils. All extant species induce characteristic eyespot galls on maple (Acer) leaves. The genus was established by American entomologist Raymond Gagné in 1983, with Acericecis ocellaris as the type species. Species are restricted to the Holarctic region.
Aciurina aplopappi
Aciurina aplopappi is a tephritid fruit fly described by Coquillett in 1894. It is placed in the genus Aciurina, a group of gall-forming or stem-boring flies associated with Asteraceae plants. The species is known from the United States, though detailed biological information remains limited. Only three observations have been recorded on iNaturalist, indicating it is rarely encountered or poorly documented.
Aciurina ferruginea
Medusa Gall Tephritid
Aciurina ferruginea is a gall-forming tephritid fly known as the Medusa Gall Tephritid. It forms distinctive pear-shaped galls on Chrysothamnus viscidiflorus (sticky rabbitbrush) by ovipositing eggs into axillary bud exudate. Adults exhibit visual communication through wing displays, which likely function in species recognition and courtship. The species has been documented in the western United States.
Aciurina trixa
Bubble-gall tephritid
Aciurina trixa is a gall-forming tephritid fly that induces spheroidal bud galls on host plants in the genus Chrysothamnus (Asteraceae). It is multivoltine with three larval instars, typically producing one larva per gall. The species exhibits sexual dimorphism: females are larger overall, while males possess enlarged forefemora that predict copulatory success. It is unusually common and abundant in New Mexico and Arizona, where it supports complex arthropod communities including 24 associated species across 6 guilds.
Adelges cooleyi
Cooley spruce gall adelgid, Douglas fir adelgid, gall adelgid
Adelges cooleyi is a gall-forming adelgid native to western North America, specifically the Rocky Mountains and Cascade Mountains. It is a host-alternating species with a complex life cycle involving two primary hosts: spruce (Picea) species as primary hosts and Douglas fir (Pseudotsuga menziesii) as the secondary host. On spruce, the adelgid induces the formation of distinctive pineapple-shaped galls at branch terminals. On Douglas fir, it produces white, cottony wax masses containing eggs but causes less conspicuous injury. The species has two generations per year and exhibits morphological dimorphism: progredientes migrate to current-year needles while sistentes settle on older needles.
Adelges laricis
Larch Woolly Aphid
Adelges laricis is a holocyclic adelgid with a complex life cycle involving two host genera: Picea (spruce) as primary host where galls form, and Larix (larch) as secondary host. The species exhibits extensive morphological polymorphism across five generations (Fundatrix, Migrans alata, Hiemosistens, Sexupara, Sexualis). First-instar nymphs are the only mobile stage; subsequent instars remain sessile with stylets permanently inserted. The species is a significant forest pest causing reduced tree vigor, needle damage, and mortality under chronic infestation.
Ametrodiplosis fistulosae
Ametrodiplosis fistulosae is a species of gall midge in the family Cecidomyiidae, described by Plakidas in 2016. The specific epithet "fistulosae" suggests an association with hollow or tubular plant structures. As a member of the genus Ametrodiplosis, it belongs to a group of cecidomyiid flies known for inducing galls on plants. The species is documented in the Catalogue of Life and has been recorded on iNaturalist with 25 observations.
Andricus burnetti
Andricus burnetti is a species of gall wasp in the family Cynipidae, a group renowned for inducing diverse and structurally complex galls on oak trees. As a member of the genus Andricus, this species participates in the intricate life cycle characteristic of cynipid wasps, where females lay eggs in oak tissues and the developing larvae secrete substances that redirect plant growth to form specialized galls. The species was described by Burnett, for whom it is named. Like many Andricus species, it likely exhibits host specificity to particular oak species, though detailed biological accounts remain limited in published literature.
Andricus quercusformosus
Andricus quercusformosus is a species of cynipid gall wasp in the family Cynipidae. The species was originally described by Bassett in 1864 under the basionym Cynips quercusformosa. Like other members of the genus Andricus, this species is associated with oak trees (Quercus spp.) as host plants. The specific epithet "quercusformosus" derives from Latin, combining "quercus" (oak) with "formosus" (beautiful), likely referring to the appearance of the galls it produces. The species belongs to the highly diverse gall wasp family Cynipidae, which contains thousands of species that form characteristic galls on various plant parts.
Antistrophus silphii
Apical Rosinweed Gall Wasp
Antistrophus silphii is a gall-forming cynipid wasp native to North American prairies. The species induces stem galls on rosinweed (Silphium integrifolium), a tall prairie forb. Galls are large, solid, and succulent when young, becoming harder with age. The wasp has a single generation per year, with adults emerging in early summer.
Aphalara
jumping plant lice, psyllids
Aphalara is a genus of jumping plant lice (psyllids) in the family Aphalaridae and tribe Aphalarini. The genus contains approximately 37 recognized valid species distributed across the Palearctic, Nearctic, and Neotropical regions. Many species are specialized herbivores of Polygonaceae, particularly Polygonum and Rumex, with some groups showing strict host associations. The genus includes A. itadori, a widely studied biological control agent for invasive knotweeds (Reynoutria/Fallopia spp.) in Europe and North America. Species exhibit diverse biologies including gall induction on host plants and vibrational communication during mate search.
Asphondylia diervillae
Asphondylia diervillae is a gall midge in the family Cecidomyiidae. It is one of approximately 15 species of Asphondylia flies that induce galls on creosote bush (Larrea tridentata) in the southwestern United States and Mexico. The larvae develop within plant tissue, manipulating host plant development to form protective galls.
Asphondylia florea
Creosote Flower Gall Midge
Asphondylia neomexicana
Fourwing Saltbush Woolly Gall Midge
Asphondylia neomexicana is a gall midge in the family Cecidomyiidae, first described by Cockerell in 1896. Like other members of its genus, this species induces distinctive woolly galls on host plants. The genus Asphondylia is notable for containing numerous species that manipulate plant growth to form protective structures for their developing larvae. Based on its specific epithet and the common name "Fourwing Saltbush Woolly Gall Midge," this species appears associated with fourwing saltbush (Atriplex canescens) or related Atriplex species in arid western North American habitats.
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.
Asphondylia websteri
alfalfa gall midge
Asphondylia websteri, commonly known as the alfalfa gall midge, is a species of gall midge in the family Cecidomyiidae. Like other members of its genus, this species induces gall formation on host plants. Research has documented its association with numerous native American plants, particularly in the Asteraceae family. The species was described by Felt in 1917.
Asteromyia clarkei
Asteromyia clarkei is a gall midge species in the family Cecidomyiidae, first described by Felt in 1909. The genus Asteromyia comprises gall-inducing midges that form characteristic star-shaped or rosette galls on asteraceous host plants. As a member of this genus, A. clarkei is associated with inducing galls on goldenrod (Solidago) species. The species is known from North America with documented observations primarily from the United States.
Asteromyia gutierreziae
matchweed stem gout
Asteromyia gutierreziae is a gall midge in the family Cecidomyiidae that induces galls on various plants in the Asteraceae family. The species is black in color and measures approximately 3–5 mm in length. It has been documented on multiple host plants including species of Gutierrezia, Baccharis, and related genera. The common name 'matchweed stem gout' reflects its association with matchweed plants and its gall-forming habit.
Bucculatrix simulans
Bucculatrix simulans is a small ribbed cocoon-making moth in the family Bucculatricidae, described by Annette Frances Braun in 1963. It occurs in central North America from Texas northward to Iowa and east to Ohio. Adults are active primarily from January through July, with a wingspan of 9.5–10 mm. The larvae are known to feed on Helianthus (sunflower) species and create distinctive stem galls.
Burnettweldia
Burnettweldia is a genus of oak gall wasps (Cynipidae: Cynipini) established in 2021, containing five species distributed in the Nearctic region. Species were transferred from other genera or newly described based on morphological and molecular data. The genus is associated with oak hosts (Quercus), inducing galls on various plant tissues.
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.
Caloptilia murtfeldtella
Caloptilia murtfeldtella is a small gracillariid moth known for its distinctive larval biology. The species creates stem galls on Penstemon plants, with larvae developing inside individual galls before emerging through a specially prepared epidermal window. Adults overwinter and have been recorded across multiple U.S. states and Canadian provinces. The species was named in honor of naturalist Mary Murtfeldt, who collected the type specimens.
Caryomyia arcuata
Hickory Sombrero Gall Midge
Caryomyia arcuata is a gall midge species in the family Cecidomyiidae, described by Gagné in 2008. It is known by the common name "Hickory Sombrero Gall Midge," referencing the distinctive gall structure it induces on hickory trees. As a member of the genus Caryomyia, this species is part of a group specialized in forming galls on Carya (hickory) species. The species has been documented through iNaturalist observations, indicating ongoing citizen science documentation of its occurrence.
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.
Caryomyia caryae
Hickory Sticky Globe Gall Midge
Caryomyia caryae is a gall midge in the family Cecidomyiidae that induces distinctive globular galls on hickory leaves. The species is one of several gall-forming insects associated with Carya species in eastern North America. Like other cecidomyiids, it manipulates host plant tissue development through chemical secretions to create protective structures for its larvae.
Caryomyia eumaris
Caryomyia eumaris is a gall midge species in the family Cecidomyiidae, described by Gagné in 2008. It belongs to a genus specialized in inducing galls on hickory and pecan trees (Carya species). Like other members of Caryomyia, this species is associated with nut-bearing Carya hosts. The species is documented in the southeastern United States based on iNaturalist observations.
Caryomyia flaticrustum
Hickory Puff Tart Gall Midge
Caryomyia flaticrustum is a gall midge species in the family Cecidomyiidae, described by Gagné in 2008. The species is known for inducing distinctive galls on hickory trees (Carya species). It is one of several Caryomyia species specialized on hickory hosts. The common name "Hickory Puff Tart Gall Midge" refers to the characteristic gall morphology produced on host leaves.
Caryomyia lenta
Hickory Popover Gall Midge
Caryomyia lenta is a gall midge species described by Gagné in 2008, known by the common name Hickory Popover Gall Midge. It belongs to the family Cecidomyiidae, a group of small flies whose larvae induce abnormal plant growths called galls. The species has been documented through iNaturalist observations, suggesting it is recognized by field observers, though detailed biological studies remain limited. As a member of the genus Caryomyia, it is associated with hickory trees (Carya species).
Caryomyia marginata
Caryomyia marginata is a species of gall midge in the family Cecidomyiidae, described by Gagné in 2008. The genus Caryomyia comprises gall midges that induce galls on hickory and pecan trees (Carya spp.). As a member of this genus, C. marginata is presumed to be associated with Carya host plants, though specific details of its biology remain limited in published literature.
Caryomyia purpurea
Hickory Purple Gumdrop Gall Midge
Caryomyia purpurea is a species of gall midge in the family Cecidomyiidae, described by Raymond Gagné in 2008. The species is known by the common name "Hickory Purple Gumdrop Gall Midge," indicating its association with hickory plants and the distinctive gall structures it induces. As a member of the genus Caryomyia, this species belongs to a group of gall midges specialized on Carya (hickory) species.
Caryomyia tubicola
Hickory Bullet Gall Midge
Caryomyia tubicola is a gall midge that induces distinctive bullet-shaped galls on hickory leaves. As a member of the family Cecidomyiidae, it has a complex life cycle involving both sexual and parthenogenetic generations. The species is primarily known from eastern North America, where it has been documented on Carya species.
Celticecis acuminata
Hackberry Narrow-tipped Gall Midge
Celticecis acuminata is a gall midge species in the family Cecidomyiidae, described by Gagné in 2013. It belongs to the genus Celticecis, which comprises gall midges associated with hackberry trees (Celtis spp.). The species is known to induce distinct galls on its host plants. As a member of the gall midge subfamily Cecidomyiinae, it exhibits the typical life cycle of cecidomyiids, with larvae developing within plant tissue.
Celticecis celtiphyllia
hackberry acorn gall midge
Celticecis celtiphyllia, commonly known as the hackberry acorn gall midge, is a gall-forming fly in the family Cecidomyiidae. This species induces distinctive galls on hackberry trees (Celtis species). The specific epithet 'celtiphyllia' references its association with Celtis foliage. It is one of several described species in the genus Celticecis, all of which appear to specialize on Celtis hosts.
Celticecis ovata
Hackberry Tenpin Gall Midge
Celticecis ovata is a gall midge species in the family Cecidomyiidae, described by Gagné in 2013. It induces distinctive galls on hackberry trees (Celtis spp.), specifically forming tenpin-shaped structures on leaves. The species is part of a genus specialized on Celtis hosts, with multiple Celticecis species known to produce morphologically distinct galls on the same host genus.
Celticecis pubescens
Hackberry Pubescent Gall Midge
Celticecis pubescens, commonly known as the hackberry pubescent gall midge, is a species of gall midge in the family Cecidomyiidae. The species was first described by Patton in 1897. As a gall midge, it induces abnormal plant growths (galls) on its host plant. The genus Celticecis is associated with hackberry trees (Celtis species).
Ceruraphis viburnicola
Snowball Aphid
An aphid species found in spring and autumn on Viburnum hosts in North America. It induces curled leaf galls on primary hosts. The secondary hosts remained unrecorded as of 1960. The apterous viviparous female was first described in a 1960 Canadian Entomologist paper.
Chirosia betuleti
Knotting Gall
Chirosia betuleti is a gall-forming fly in the family Anthomyiidae that induces characteristic knotting galls on fern fronds. The species is best known through the distinctive damage it causes rather than adult morphology. It has been recorded across much of Europe, with extensive documentation in the United Kingdom. The gall structure and larval mining behavior are well-studied, though adult fly biology remains less documented.
Cirrospilini
Cirrospilini is a tribe within the subfamily Eulophinae (Hymenoptera: Eulophidae) comprising approximately 17 genera and nearly 300 species. Members are ectoparasitoids that attack immature stages of Diptera, Lepidoptera, and Coleoptera in semi-concealed habitats. Some species function as obligate or facultative hyperparasitoids, and a few are gall-formers. Phylogenetically, the tribe is considered monophyletic and the sister-group to Eulophini plus Elasmini.
Clinodiplosis rhododendri
Rhododendron Gall Midge
Clinodiplosis rhododendri is a gall midge in the family Cecidomyiidae that induces gall formation on rhododendron plants. The species is known primarily from limited observations, with most records documenting its association with cultivated and native Rhododendron species. As a gall-forming insect, it manipulates host plant tissue to create protected feeding structures. The species is of interest to horticulturists due to its potential impact on ornamental rhododendrons.
Clinodiplosis undescribed-species-on-persicaria
An undescribed species of gall midge in the genus Clinodiplosis (family Cecidomyiidae) associated with Persicaria plants. The species has not received formal taxonomic description, though its existence is documented through gall formation on host plants. As with other Clinodiplosis species, it likely induces characteristic plant galls during larval development. The specific epithet reflects its documented host association rather than a formally published name.
Clinodiplosis verbenae
Clinodiplosis verbenae is a gall midge species in the family Cecidomyiidae, described by Beutenmüller in 1907. The specific epithet 'verbenae' indicates an association with plants in the genus Verbena. Like other members of Clinodiplosis, this species is presumed to induce galls on host plants, though specific gall morphology has not been well documented in accessible literature. The species is known from relatively few observations.
Coccotorus
plum gouger
Coccotorus is a genus of true weevils in the family Curculionidae, containing approximately six described species. The genus is placed in the tribe Anthonomini within the subfamily Curculioninae. Some species are associated with gall formation on host plants. One species, C. beijingensis, has been studied for its complete mitochondrial genome and its phylogenetic relationship to the genus Anthonomus.
Contarinia undescribed-species-on-boxelder
An undescribed species of gall midge in the genus Contarinia associated with boxelder (Acer negundo). As a member of the family Cecidomyiidae, this species likely forms galls or induces other plant growth abnormalities during larval development, though formal taxonomic description remains pending. The specific epithet reflects its documented association with this host plant rather than a formally published species name.
Contarinia undescribed-species-on-milkweed
An undescribed species of gall midge in the genus Contarinia (family Cecidomyiidae) that forms galls on milkweed plants (Asclepias spp.). The species has not been formally described in scientific literature but has been documented in field observations. As with other Contarinia species, it likely has a narrow host association with milkweed. The informal designation indicates ongoing taxonomic work is needed.
Contarinia zauschneriae
California fuchsia gall midge
Contarinia zauschneriae is a gall midge species that induces distinctive roselle-form bud galls on Epilobium canum (California fuchsia), a flowering plant native to western North America. The species was first described by Ephraim Felt in 1912 based on specimens collected in the Puente Hills near Whittier, California. The galls are structurally complex, mimicking rosebuds in both form and coloration.
Craneiobia
Craneiobia is a genus of gall midges in the family Cecidomyiidae, established by Kieffer in 1913. The genus contains at least two described species that induce distinctive tube-like galls on leaves of Cornus (dogwood) plants. These insects are specialized gall-formers with a narrow host association.
Craneiobia tuba
Craneiobia tuba is a gall midge in the family Cecidomyiidae that induces distinctive cylindrical galls on dogwood leaves. The species is known from four host plants in the genus Cornus. Adults emerge in spring to lay eggs on unfolding leaves, with galls developing by summer. Larvae complete development in fall, then overwinter underground in cocoons.
Ctenodactylomyia watsoni
Sea Grape Gall Midge
Ctenodactylomyia watsoni is a gall midge species in the family Cecidomyiidae, commonly known as the Sea Grape Gall Midge. It induces galls on sea grape (Coccoloba uvifera), a coastal shrub native to tropical and subtropical regions of the Americas. The species is well-documented through iNaturalist observations, with over 790 records, indicating it is relatively common and readily observed by naturalists in its range. As a gall-forming insect, it manipulates host plant tissue to create protected structures for larval development.