Eriophyidae
Guides
Aceria
gall mites, eriophyid mites, four-legged mites
Aceria is a large genus of eriophyid mites (family Eriophyidae) containing over 900 described species. These microscopic, worm-like arachnids are obligate plant parasites that induce distinctive plant growth abnormalities including galls, erinea, and witches' brooms. Some species are economically significant agricultural pests, while others have been deployed as biological control agents against invasive weeds. The genus exhibits extreme host specificity, with most species restricted to a single plant species or genus.
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 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 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 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 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.
Aculops ailanthii
Ailanthus leafcurl mite
Aculops ailanthii, commonly known as the Ailanthus leafcurl mite, is an eriophyid mite that infests Ailanthus altissima (tree-of-heaven). This species produces subtle leaf symptoms—undercurled, wrinkled, and glossier foliage—rather than the conspicuous galls typical of many eriophyid mites. The mites themselves are tiny, whitish, and difficult to locate on leaf undersides. The species has been proposed as a potential biocontrol agent against invasive Ailanthus populations in North America, though it remains poorly studied.
Aculus
Aculus is a genus of eriophyid mites (Eriophyidae: Phyllocoptinae) comprising numerous species that are predominantly plant-associated. Species in this genus exhibit diverse host relationships, with documented associations spanning at least 15 plant families including Rosaceae, Salicaceae, Fabaceae, and Hypericaceae. Most described species are vagrants on leaf surfaces, though some form galls or cause leaf deformation. Several species are economically significant agricultural pests, while others have been investigated for biological control potential against invasive plants.
Eriophyes neoessigi
cottonwood catkin gall mite
Eriophyes neoessigi is an eriophyid mite species commonly known as the cottonwood catkin gall mite. It is documented on iNaturalist with 168 observations. The species belongs to the genus Eriophyes, which includes gall-forming mites that induce characteristic plant deformities. Unlike the related Eriophyes dimocarpi, which causes witches' broom disease in longan trees, E. neoessigi is associated with cottonwood (Populus spp.) and specifically targets catkins.
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.