Galls caused by the larvse, nymphs, and imagines of 

 Eriophyes aucuparise 



on 



the leaves of Pyrus aucuparia Gsertn. 



PLATE 4G. 

 Synonymy of Mite. 

 Eriopliyes pyri Nal. 



Habitat of the Mountain Ash.— Distributed throughout 

 Britain in woods, plantations, and parks. 



Position of the Galls. — On both sides of the leaflets and 

 on the rachis. 



Manner of GRO^VTH.— Glabrous ; gregarious, coalescing into 

 patches. 



Colour. — Pale green, yellow, orange-yellow, red, reddish brown. 



Average Dimensions of a Mature Specimen. 



Height, I mm. ; breadth, 2 mm. ; circumference, 6 mm. 



May be sought during the months of May to October. 



The Growth is complete by the end of August. 



These galls are very similar to those caused by Eriopliyes 

 piri (p. 150) on leaves of Pyrus communis, not only in size, 

 form, and colour, but also as regards coalescence, although 

 this latter peculiarity is not quite so persistent. The swelling 

 is in the form of a lenticular pustule, more fully developed 

 when on the under surface of the leaflet than when on the 

 upper. Although each leaflet may be thickly covered with 

 the pustules, no appreciable difference is caused in the outline. 

 The author has only twice found these galls, and he believes 

 them to be both local and uncommon. See also plate 76. 



The illustration is of specimens gathered at Guestling, 

 near Hastings, by the author. 



124 



