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 ...
that chemically induces a pouch
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 ...
to develop as a sub-spherical distortion rising up from the upper surface of the lamina of leaves of blackthorn shrubs ''
Prunus padus
''Prunus padus'', known as bird cherry, hackberry, hagberry, or Mayday tree, is a flowering plant in the rose family. It is a species of cherry, a deciduous small tree or large shrub up to tall. It is the type species of the subgenus '' Padus' ...
'', ''
Prunus spinosa
''Prunus spinosa'', called blackthorn or sloe, is a species of flowering plant in the rose family Rosaceae. The species is native to Europe, western Asia, and regionally in northwest Africa. It is locally naturalized in New Zealand, Tasmania, ...
'' and other ''Prunus'' species. Synonyms are ''Phytoptus padi'' Nalepa, 1890 and "''Eriophyes padi'' (Nalepa, 1890)", non ''Eriophyes padi'' Domes, 2000.Danish Nature Retrieved 2012-12-9]Hancy, Page 97
Description
The gall's appearance on the upper surface is sub-spherical pustules, hairy and opening below, often clustering along the midrib,Redfern, Page 395 but also found over the whole leaf lamina surface and may vary in colour from pale yellow-green to deep red. The adult mite lives on sap, sucked from the cell tissues. The leaf surface can be so densely covered with galls that it becomes deformed and wrinkled.
Distribution
The species is found in Denmark as well as in England and Scotland.NBN Gateway Retrieved : 2012-12-09
Gallery
File:Eriophyes padi - Lower epidermis.JPG, The lower epidermis of a Blackthorn leaf with ''P. eupadi'' galls.
File:Leaf galls on bird cherry - geograph.org.uk - 1285822.jpg, ''P.eupadi'' on a Bird Cherry leaf.
References
;Notes
;Sources
# Hancy, Rex (2000). ''The Study of Plant Galls in Norfolk''. The Norfolk and Norwich Naturalists' Trust.
# Redfern M. and Shirley P. (2002). ''British Plant Galls.'' FSC Publications. .
# Stubbs, F.B. ed. (1986). ''Provisional Keys to British Plant Galls''.
British Plant Gall Society
The British Plant Gall Society is a voluntary organisation which encourages cecidology, the study of plant galls, in the British Isles. It was formed in 1985. Its biannual journal, ''Cecidology'', is edited by Michael Chinery.
Notable people ...