Eriophyoidea are a superfamily of

herbivorous A herbivore is an animal anatomically and physiologically evolved to feed on plants, especially upon vascular tissues such as foliage, fruits or seeds, as the main component of its diet. These more broadly also encompass animals that eat n ...

mite Mites are small arachnids (eight-legged arthropods) of two large orders, the Acariformes and the Parasitiformes, which were historically grouped together in the subclass Acari. However, most recent genetic analyses do not recover the two as eac ...

s. All post-embryonic

instars An instar (, from the Latin ''wikt:instar#Latin, īnstar'' 'form, likeness') is a developmental stage of arthropods, such as insects, which occurs between each ecdysis, moult (''ecdysis'') until sexual maturity is reached. Arthropods must shed the ...

lack the third and fourth pairs of legs, and the respiratory system is also absent. The taxonomy of this group has always been confused. There were families created for few or even one species, i.e. Ashieldophyidae Mohanasundaram, 1984 and Pentasetacidae Shevchenko, 1991 but these families were placed by J. W. Amrine and T. A. Stasny within larger groups. Today the following three families are believed to belong to superfamily Eriophyoidea: *

Eriophyidae Eriophyidae is a family of more than 200 genera of mites, which live as plant parasites, commonly causing galls or other damage to the plant tissues and hence known as gall mites. About 3,600 species have been described, but this is probably l ...

Nalepa, 1898 * Phytoptidae Murray, 1877 * Diptilomiopidae Keifer, 1944

Description

Eriophyoids are no more than 0.5 mm long and usually 0.12 mm long or less. The body shape is usually long and wormlike (vermiform), but it can rarely be flattened or lobulate. At the front end of the body are the mouthparts, a pair of minute

palps Pedipalps (commonly shortened to palps or palpi) are the secondary pair of forward appendages among chelicerates – a group of arthropods including spiders, scorpions, horseshoe crabs, and sea spiders. The pedipalps are lateral to the chelicera ...

and two pairs of legs. The posterior part of the body is annulate, meaning it is covered in rings (annuli). The body and legs have some

setae In biology, setae (; seta ; ) are any of a number of different bristle- or hair-like structures on living organisms. Animal setae Protostomes Depending partly on their form and function, protostome setae may be called macrotrichia, chaetae ...

but fewer than in other mites (i.e. setation is reduced). In terms of colour, eriophyoids are white to yellowish. Females have a genital flap posterior to the coxae of the second pair of legs, and they lack genital papillae. Males have reduced genital flaps. In some species, adult females have two different forms, the protogyne and the deutogyne. Deutogynes normally resemble protogynes, but they can also show differences such as red colouration, different microtubercle structure, broader prodorsal shield, larger body size and dorsal annuli being more sclerotised. This may cause protogynes and deutogynes to be mistaken for different species.

Reproduction

Eriophyoidea reproduce through both

internal fertilisation Internal fertilization is the union of an egg and sperm cell during sexual reproduction inside the female body. Internal fertilization, unlike its counterpart, external fertilization, brings more control to the female with reproduction. For intern ...

and

arrhenotoky Arrhenotoky (from Greek ἄρρην ''árrhēn'' "male" and τόκος ''tókos'' "birth"), also known as arrhenotokous parthenogenesis, is a form of parthenogenesis in which unfertilized eggs develop into males. In most cases, parthenogenesis pro ...

(i.e. females producing male offspring without being fertilised). Fertilisation involves males depositing stalked

spermatophores A spermatophore, from Ancient Greek σπέρμα (''spérma''), meaning "seed", and -φόρος (''-phóros''), meaning "bearing", or sperm ampulla is a capsule or mass containing spermatozoa created by males of various animal species, especially ...

on a plant. Females capture spermatophores, crush them to extract the

sperm Sperm (: sperm or sperms) is the male reproductive Cell (biology), cell, or gamete, in anisogamous forms of sexual reproduction (forms in which there is a larger, female reproductive cell and a smaller, male one). Animals produce motile sperm ...

and store this in

spermathecae The spermatheca (pronounced : spermathecae ), also called ''receptaculum seminis'' (: ''receptacula seminis''), is an organ of the female reproductive tract in insects, e.g. ants, bees, some molluscs, Oligochaeta worms and certain other inver ...

. Female eriophyoids lay spherical eggs.

Ecology

All of the Eriophyoidea are parasites of plants. This is reflected in common names such as "blister mites", "bud mites", "gall mites" and "rust mites". The superfamily includes many important crop pests, some of which transmit plant diseases. As previously mentioned, some eriophyoid species can produce two forms of females. The deutogyne form is more tolerant of adverse conditions than the protogyne form. This polymorphism mainly occurs in species on

deciduous In the fields of horticulture and botany, the term deciduous () means "falling off at maturity" and "tending to fall off", in reference to trees and shrubs that seasonally shed Leaf, leaves, usually in the autumn; to the shedding of petals, aft ...

plants that experience well-defined winters.

Evolution

The group is ancient. Forms with two pairs of legs, already similar to the modern ones, have been found in

Triassic The Triassic ( ; sometimes symbolized 🝈) is a geologic period and system which spans 50.5 million years from the end of the Permian Period 251.902 million years ago ( Mya), to the beginning of the Jurassic Period 201.4 Mya. The Triassic is t ...

amber Amber is fossilized tree resin. Examples of it have been appreciated for its color and natural beauty since the Neolithic times, and worked as a gemstone since antiquity."Amber" (2004). In Maxine N. Lurie and Marc Mappen (eds.) ''Encyclopedia ...

from Italy: ''

Ampezzoa ''Ampezzoa triassica'' is an extinct species of gall mite described from the Carnian of northeastern Italy. It lived as a parasite of Cheirolepidiaceae trees. The only known specimen, preserved in amber Amber is fossilized tree resin. Ex ...

,'' ''

Triasacarus ''Triasacarus fedelei'' is an extinct species of gall mite described from the Carnian of northeastern Italy. It lived as a parasite of Cheirolepidiaceae trees. The only known specimen, preserved in amber, is 0.210 mm long. Along with '' A ...

,'' '' Minyacarus'' and '' Cheirolepidoptus,'' which were specialised on extinct conifers of family

Cheirolepidiaceae Cheirolepidiaceae (also spelled Cheirolepidaceae) is an extinct family of conifers. They first appeared in the Triassic, and were a diverse and common group of conifers during most of the Mesozoic era, primarily at low latitudes, where they often ...

. The four genera were subsequently placed in a new extinct clade, the Triasacaroidea, which is the sister group to the extant Eriophyoidea.

Phylogeny

While traditionally considered members of the clade

Trombidiformes Trombidiformes is a large, diverse order of mites. Taxonomy In 1998, Trombidiformes was divided into the Sphaerolichida and the Prostigmata. The group has few synapomorphies by which it can be defined, unlike the other major group of acariform ...

, they have been found to be an early diverging mite clade outside the clade containing Trombidiformes in recent morphological and genomic analyses.

References

{{Taxonbar, from=Q5389487 Sarcoptiformes Arthropod superfamilies hu:Gubacsatka-félék