Galls or cecidia are a kind of swelling growth on the external tissues of plants, fungi, or animals. Plant galls are abnormal outgrowths of plant tissues, similar to benign tumors or warts in animals. They can be caused by various parasites, from viruses, fungi and bacteria, to other plants, insects and mites. Plant galls are often highly organized structures so that the cause of the gall can often be determined without the actual agent being identified. This applies particularly to some insect and mite plant galls. The study of plant galls is known as cecidology.
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 less than 10% of the actual number existing in this poorly researched family. They are microscopic mites and are yellow to pinkish white to purplish in color. The mites are worm like, and have only two pairs of legs. Their primary method of population spread is by wind. They affect a wide range of plants, and several are major pest species causing substantial economic damage to crops. Some species, however, are used as biological agents to control weeds and invasive plant species.
Muehlenbeckia complexa, commonly known as pohuehue, although this name also applies to some other climbers such as Muehlenbeckia australis.
Feltiella acarisuga is a species of predatory gall midges which will feed on various species of spider mites. It is especially common when spider mites occur in colonies. It requires a high spider mite density and high humidities to become established.
Tydeus eriophyes is a species of mite belonging to the family Tydeidae. This small oval, eyeless mite is around 300 μm in length with a soft body covered in striations. It can be distinguished from similar species by the bluntly pointed, rod-like dorsal setae. This species is associated with the gall mite Eriophyes vitis on grapevines in the vicinity of Grabouw, South Africa.
Feniseca tarquinius, the harvester, is a butterfly of the family Lycaenidae, and the only member of the monotypic genus Feniseca. It is found in eastern North America.
Rabdophaga rosaria is a gall midge which forms Camellia galls or terminal rosette gall on willow species. It was first described by Hermann Loew in 1850.
Aceria sheldoni, commonly called the citrus bud mite, is a species of mite belonging to the family Eriophyidae. It feeds in leaf- and flower-buds of Citrus spp., causing deformation to leaves, flowers and fruit, and is a worldwide pest of citrus fruit production.
Eriophyes tiliae is a mite that forms the lime nail gall or bugle gall. It develops in a chemically induced gall; an erect, oblique or curved distortion rising up from the upper surface of the leaves of the lime (linden) trees, such as the large-leaved lime tree Tilia platyphyllos, the common lime tree Tilia × europaea, etc.
Eriophyes padi is a gall-forming mite that causes cherry pouch galls on black cherry trees.
Celastrina serotina, the cherry gall azure, is a butterfly of the family Lycaenidae. It is found across North America as far north as the treeline. Its flight time is between mid-May and mid-June in eastern Ontario after the spring azure and before the summer azure. The larva has been reported to feed on galls of eriophyid mites and apparently also on the mites themselves, making them one of the rare species of carnivorous Lepidoptera. It is commonly found around woodland roads of upland mixed deciduous hardwood forests which are surrounded by wetlands.
Aceria guerreronis, the coconut mite, is an eriophyid mite which infests coconut plantations. It is economically devastating, and can destroy up to 60% of coconut production. The immature nuts are infested and injured by mites feeding in the portion covered by the perianth of the immature nut.
Eriophyes is a genus of acari that forms galls, specially on trees of the family Rosaceae. Some are called blister mites. The blue butterfly Celastrina serotina has been reported to feed on these galls and also on the mites, making it one of the uncommon carnivorous Lepidoptera.
Phytoptus avellanae is an acarine gall-mite species inducing big bud galls of up to 10 millimetres (0.39 in) across, sometimes slightly open, on the buds of hazel and on filbert. Synonyms include Phytocoptella avellanae, Eriophyes avellanae, Calycophthora avellanae, Phytoptus coryli, Phytoptus pseudogallarum, and Acarus pseudogallarum. The mites are white, about 0.3 mm long, with numerous tergites and sternites. Two forms of P. avellanae exist, a gall causer and a vagrant form that has a more complex life-cycle and does not form galls.
Phyllocoptes eupadi is a mite that chemically induces a pouch gall to develop as a sub-spherical distortion rising up from the upper surface of the lamina of leaves of blackthorn shrubs Prunus padus, Prunus spinosa and other Prunus species. Synonyms are Phytoptus padi Nalepa, 1890 and "Eriophyes padi ", non Eriophyes padi Domes, 2000.
Vasates quadripedes, the maple bladder-gall mite, is an eriophyid mite in the genus Vasates, which causes galls on the leaves of silver maple, red maple (A. rubrum), and sugar maple (A. saccharum). The gall is rounded, sometimes elongate, and has a short, thin neck. Typically, galls are 2–3 millimetres (0.079–0.118 in) in diameter, and may be numerous on the upper surfaces of leaves. They have an opening in the lower surface. At first they are yellowish-green or bright red, later they become dark red and black.
Eriophyes vitis, also known as grape erineum mite or blister mite, is a mite species in the genus Eriophyes infecting grape leaves. E. vitis has spread worldwide and has three distinct strains: a leaf-curling strain, a blister-causing strain, and a strain that stunts the growth of buds. It is a vector of grapevine pinot gris virus and grapevine inner necrosis virus.
Eriophyes laevis is a gall mite which makes small, pimple-like galls on the leaves of alder. The mite was first described by the Austrian zoologist, Alfred Nalepa in 1889 and is found in Europe and North America.
