''Aculus laevis'' is a species of mite which causes

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

sallows Sallows is a fell in the English Lake District, rising between the valleys of Kentmere and Troutbeck. It is the highest point in the upland area to the south of Garburn Pass, variously termed Kentmere Park and Applethwaite Common on Ordnance S ...

(''Salix'' species). It was first described by

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 1892.

Description of the gall

The gall is a 1–2 mm pouch on the upper side of the leaves of sallows and their hybrids. At first they are yellowish-green and turn to a reddish-brown later. On the underside of the leaf is an elliptical opening which has protruding hairs and contains a single mite. There can be up to thirty galls on a leaf. The gall has been found on eared willow ( ''S. aurita''), goat willow ( ''S. caprea''), grey willow ( ''S. cinerea'') and their hybrids. ;Similar species The similar galls on the longer leaf willows such as crack willow ( ''S. fragilis''), are caused by ''A. tetanothrix''. Redfern et al (2011) state that the identification of all mite galls on ''Salix'' species is tentative and there are probably unnamed species yet to be described. In addition the mites should be verified by an expert.

Distribution

''Aculus laevis'' has been recorded from Austria, Croatia, Finland, France, Germany, Great Britain (England, Scotland and Wales), Hungary, Ireland and Slovenia.

References

External links

Dorset Nature
{{Taxonbar, from=Q49627053 Eriophyidae Animals described in 1892 Arachnids of Europe Taxa named by Alfred Nalepa Willow galls