''Eriophyes laevis '' is a gall

mite Mites are small arachnids (eight-legged arthropods). Mites span two large orders of arachnids, the Acariformes and the Parasitiformes, which were historically grouped together in the subclass Acari, but genetic analysis does not show clear evid ...

which makes small, pimple-like

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 the leaves of alder (''Alnus'' species). The mite was first described by the Austrian

zoologist Zoology ()The pronunciation of zoology as is usually regarded as nonstandard, though it is not uncommon. is the branch of biology that studies the Animal, animal kingdom, including the anatomy, structure, embryology, evolution, Biological clas ...

Alfred Nalepa Alfred Nalepa (19 December 1856, in Werschetz – 11 December 1929, in Baden bei Wien) was an Austrian zoologist specializing in the field of acarology. He studied natural sciences at the University of Vienna, and from 1886 was associated with th ...

in 1889 and is found in Europe and North America.

Description of the gall

''Eriophyes laevis '' makes small, more or less, pimple-like galls, up to 2 mm in diameter. They can cover most of the leaf which can restrict growth. Each gall has a narrow opening on the underside of the leaf. The galls are green at first but usually become purple or red later in the year. The mites leave the gall in autumn and spend the winter in empty alder cones or bark crevices. Species of tree galled include common alder (''

Alnus glutinosa ''Alnus glutinosa'', the common alder, black alder, European alder, European black alder, or just alder, is a species of tree in the family Betulaceae, native to most of Europe, southwest Asia and northern Africa. It thrives in wet locations whe ...

''), grey alder ('' Alnus incana'') & subsp. ''rugosa'' + ''tenuifolia'', x ''pubescens'', red alder ('' Alnus rubra'') and green alder ('' Alnus alnobetula''). Leaves are occasionally infected by both this species and

Eriophyes inangulis ''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 ''Alnus glutinosa'', ...

. Identification of gall mites on alder is tentative and the mites need to be examined for positive identification. ;Inquiline '' Diptacus sacramentae'' are mites found on the underside of leaves and also live commensally in the gall as an inquiline. ''D. sacramentae'' can also occur as an inquiline of ''E. inangulis''.

Distribution

The mite is found in Europe and the United States of America.

References

External links

Aphotofauna
Eriophyidae Animals described in 1889 Arachnids of Europe Arachnids of North America Galls Taxa named by Alfred Nalepa {{Trombidiformes-stub