''Eriosoma ulmi'', the elm-currant aphid, is a species of

aphid Aphids are small sap-sucking insects and members of the superfamily Aphidoidea. Common names include greenfly and blackfly, although individuals within a species can vary widely in color. The group includes the fluffy white woolly aphids. A t ...

in the family

Aphididae The Aphididae are a very large insect family in the aphid superfamily ( Aphidoidea), of the order Hemiptera. These insects suck the sap from plant leaves. Several thousand species are placed in this family, many of which are considered plant/cro ...

found in Asia and Europe. It is a true bug and sucks sap from plants. It was described by

Carl Linnaeus Carl Linnaeus (; 23 May 1707 – 10 January 1778), also known after his ennoblement in 1761 as Carl von Linné Blunt (2004), p. 171. (), was a Swedish botanist, zoologist, taxonomist, and physician who formalised binomial nomenclature, the ...

in his ''

Systema Naturae ' (originally in Latin written ' with the ligature æ) is one of the major works of the Swedish botanist, zoologist and physician Carl Linnaeus (1707–1778) and introduced the Linnaean taxonomy. Although the system, now known as binomial nomen ...

'', published in 1758. The mite causes abnormal plant growths, known as

gall Galls (from the Latin , 'oak-apple') or ''cecidia'' (from the Greek , anything gushing out) 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 be ...

s on their primary host, elm trees ''(

Ulmus Elms are deciduous and semi-deciduous trees comprising the flowering plant genus ''Ulmus'' in the plant family Ulmaceae. They are distributed over most of the Northern Hemisphere, inhabiting the temperate and tropical-montane regions of Nor ...

'' species). To complete there life-cycle they feed on a secondary host, the roots of currant bushes (''

Ribes ''Ribes'' is a genus of about 200 known species of flowering plants, most of them native to the temperate regions of the Northern Hemisphere. The various species are known as currants or gooseberries, and some are cultivated for their edible f ...

'' species).

Description of the gall

;Primary host The galls are yellowish-green or pinkish, contain wax and form when one half of a leaf becomes crinkled and roll inwards to form a tubular pouch. They are found on American elm (''

Ulmus americana ''Ulmus americana'', generally known as the American elm or, less commonly, as the white elm or water elm, is a species of elm native to eastern North America, naturally occurring from Nova Scotia west to Alberta and Montana, and south to Flor ...

''), wych elm (''

Ulmus glabra ''Ulmus glabra'' Hudson, the wych elm or Scots elm, has the widest range of the European elm species, from Ireland eastwards to the Urals, and from the Arctic Circle south to the mountains of the Peloponnese and Sicily, where the species reaches i ...

''), field elm (''

Ulmus minor ''Ulmus minor'' Mill., the field elm, is by far the most polymorphic of the European species, although its taxonomy remains a matter of contention. Its natural range is predominantly south European, extending to Asia Minor and Iran; its northern ...

''), English elm (''

Ulmus procera The field elm (''Ulmus minor'') cultivar 'Atinia' , commonly known as the English elm, formerly common elm and horse may, Republished 1978 by EP Publishing, Wakefield. and more lately the Atinian elm was, before the spread of Dutch elm disea ...

''), Siberian elm (''

Ulmus pumila ''Ulmus pumila'', the Siberian elm, is a tree native to Asia. It is also known as the Asiatic elm and dwarf elm, but sometimes miscalled the 'Chinese Elm' (''Ulmus parvifolia''). ''U. pumila'' has been widely cultivated throughout Asia, Nor ...

'') and rock elm (''

Ulmus thomasii ''Ulmus thomasii'', the rock elm or cork elm (or orme liège in Québec), is a deciduous tree native primarily to the Midwestern United States. The tree ranges from southern Ontario and Quebec, south to Tennessee, west to northeastern Kansas, ...

''). Numerous aphids living in the gall in spring and early summer, are browish to dull green and covered in wax. Winged aphids (all female) leave the gall in June and July, mating and living in the secondary host; currant bushes. The aphids live on the roots of currant bushes where they reproduce. The male and female progeny fly back to the elms in the autumn where the mated females lay eggs which overwinter.

Predator

Anthocoris gallarumulmi ''Anthocoris gallarumulmi'' is a true bug in the family Anthocoridae. The species is a West Palearctic species found on aphid-galled leaves of ''Ulmus minor'' and is a predator of the aphid '' Eriosoma ulmi'' It is also associated with aphid-l ...

'' is a

predator Predation is a biological interaction where one organism, the predator, kills and eats another organism, its prey. It is one of a family of common feeding behaviours that includes parasitism and micropredation (which usually do not kill th ...

of the aphids in the gall.

Similar galls

'' Eriosoma grossulariae'' galls and aphids are similar but are not covered or contain wax.

Distribution

The aphid is found in Asia and most of Europe. In Asia it is found in the

Oriental Region The Indomalayan realm is one of the eight biogeographic realms. It extends across most of South and Southeast Asia and into the southern parts of East Asia. Also called the Oriental realm by biogeographers, Indomalaya spreads all over the Ind ...

and

Near East The ''Near East''; he, המזרח הקרוב; arc, ܕܢܚܐ ܩܪܒ; fa, خاور نزدیک, Xāvar-e nazdik; tr, Yakın Doğu is a geographical term which roughly encompasses a transcontinental region in Western Asia, that was once the hist ...

, while in Europe from

Russia Russia (, , ), or the Russian Federation, is a List of transcontinental countries, transcontinental country spanning Eastern Europe and North Asia, Northern Asia. It is the List of countries and dependencies by area, largest country in the ...

Ireland Ireland ( ; ga, Éire ; Ulster Scots dialect, Ulster-Scots: ) is an island in the Atlantic Ocean, North Atlantic Ocean, in Northwestern Europe, north-western Europe. It is separated from Great Britain to its east by the North Channel (Grea ...

and the

Iberian Peninsula The Iberian Peninsula (), ** * Aragonese and Occitan: ''Peninsula Iberica'' ** ** * french: Péninsule Ibérique * mwl, Península Eibérica * eu, Iberiar penintsula also known as Iberia, is a peninsula in southwestern Europe, defi ...

Scandinavia Scandinavia; Sámi languages: /. ( ) is a subregion#Europe, subregion in Northern Europe, with strong historical, cultural, and linguistic ties between its constituent peoples. In English usage, ''Scandinavia'' most commonly refers to Denmark, ...

. In

Great Britain Great Britain is an island in the North Atlantic Ocean off the northwest coast of continental Europe. With an area of , it is the largest of the British Isles, the largest European island and the ninth-largest island in the world. It is ...

it is common and widespread.

References

{{Taxonbar, from=Q11120326 ulmi Gall-inducing insects Hemiptera of Asia Hemiptera of Europe Insects described in 1758 Taxa named by Carl Linnaeus