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.
Tilia is a genus of about 30 species of trees or bushes, native throughout most of the temperate Northern Hemisphere. The tree is known as linden for the European species, and basswood for North American species. In Britain and Ireland they are commonly called lime trees, although they are not related to the citrus lime. The genus occurs in Europe and eastern North America, but the greatest species diversity is found in Asia. In Chinese, "椴/duàn" or "椴樹/duànshù" is a general term for Tilia species. Under the Cronquist classification system, this genus was placed in the family Tiliaceae, but genetic research summarised by the Angiosperm Phylogeny Group has resulted in the incorporation of this genus, and of most of the previous family, into the Malvaceae.
Acer pseudoplatanus, known as the sycamore in the British Isles and as the sycamore maple in the United States, is a species of flowering plant in the soapberry and lychee family Sapindaceae. It is a large deciduous, broad-leaved tree, tolerant of wind and coastal exposure. It is native to Central Europe and Western Asia, from France eastward to Ukraine, northern Turkey and the Caucasus and southward in the mountains of Italy and northern Iberia.
Tilia cordata, the small-leaved lime or small-leaved linden, is a species of tree in the family Malvaceae, native to much of Europe. Other common names include little-leaf or littleleaf linden, or traditionally in South East England, pry or pry tree. Its range extends from Britain through mainland Europe to the Caucasus and western Asia. In the south of its range it is restricted to high elevations.
Tilia platyphyllos, the large-leaved lime or large-leaved linden, is a species of flowering plant in the family Malvaceae (Tiliaceae). It is a deciduous tree, native to much of Europe, including locally in southwestern Great Britain, growing on lime-rich soils. The common names largeleaf linden and large-leaved linden are in standard use throughout the English-speaking world except in the British Isles, where it is known as large-leaved lime. The name "lime", possibly a corruption of "line" originally from "lind", has been in use for centuries and also attaches to other species of Tilia. It is not, however, closely related to the lime fruit tree, a species of citrus.
Quercus pubescens, commonly known as the downy oak, pubescent oak or Italian oak, is a species of white oak native to southern Europe and southwest Asia. It is found from northern Spain (Pyrenees) and France in the West to Turkey and the Caucasus in the East.
Tilia americana is a species of tree in the family Malvaceae, native to eastern North America, from southeast Manitoba east to New Brunswick, southwest to northeast Oklahoma, southeast to South Carolina, and west along the Niobrara River to Cherry County, Nebraska. It is the sole representative of its genus in the Western Hemisphere, assuming T. caroliniana is treated as a subspecies or local ecotype of T. americana. Common names include American basswood and American linden.
Muehlenbeckia complexa is a plant commonly known as pohuehue, although this name also applies to some other climbers such as Muehlenbeckia australis.
Tilia tomentosa, known as silver linden in the US and silver lime in the UK, is a species of flowering plant in the family Malvaceae, native to southeastern Europe and southwestern Asia, from Romania and the Balkans east to western Turkey, occurring at moderate altitudes.
Andricus quercuscalicis is a gall wasp species inducing knopper galls.
Andricus foecundatrix is a parthenogenetic gall wasp which lays a single egg within a leaf bud, using its ovipositor, to produce a gall known as an oak artichoke gall, oak hop gall, larch-cone gall or hop strobile The gall develops as a chemically induced distortion of leaf axillary or terminal buds on pedunculate oak or sessile oak trees. The larva lives inside a smaller hard casing inside the artichoke and this is released in autumn. The asexual wasp emerges in spring and lays her eggs in the oak catkins. These develop into small oval galls which produce the sexual generation of wasps. A yew artichoke gall caused by the fly Taxomyia taxi also exists, but is unrelated to the oak-borne species. Previous names or synonyms for the species A. fecundator are A. fecundatrix, A. pilosus, A. foecundatrix, A. gemmarum, A. gemmae, A. gemmaequercus, A. gemmaecinaraeformis and A. quercusgemmae.
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.
The common spangle gall on the underside of leaves and the currant gall on the male catkins or occasionally the leaves, develop as chemically induced distortions on pedunculate oak, or sessile oak trees, caused by the cynipid wasp Neuroterus quercusbaccarum which has both agamic and bisexual generations.
Neuroterus albipes is a gall wasp that forms chemically induced leaf galls on oak trees which has both bisexual and agamic generations and therefore forms two distinct galls, the smooth spangle gall and Schenck's gall. Neuroterus laeviusculus and Spathegaster albipes are previous binomials found in the literature.
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.
Eriophyes inangulis is a mite that forms the alder vein angle gall. It develops in a chemically induced gall; a sub-spherical distortion rising up from the upper surface of the leaves of alder trees Alnus glutinosa along the midrib. Synonyms are Eriophyes laevis inangulis, Phytoptus laevis, and Cephaloneon pustulatum.
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.
Eucallipterus tiliae, also known as the linden aphid or lime-tree aphid, is a member of the family Aphididae. Native to Eurasia in recent times, it is now found worldwide wherever species of Tilia occur.
Tilia amurensis, the Amur lime or Amur linden, is a species of Tilia native to eastern Asia. It differs from the better-known Tilia cordata in having somewhat smaller leaves, bracts and cymes. It is an important timber tree in Russia, China and Korea, and is occasionally planted as a street tree in cities with colder climates.
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.
