Galls caused by the larvae, nymphs, and imagines of 

 Eriophyes viburni 



on 



the leaves of Viburnum opulus Linn. 



PLATE 71. 



Habitat of the Guelder Rose.— In woods, coppices, and 

 hedges, more or less plentiful throughout Britain. 



Position of the Gall.— On the upper surface and the under 

 surface of the leaf. 



Manner of Growth. — Irregular-shaped patches. 



Colour. — Reddish brown, chocolate-brown. 



Average Dimensions of a Mature Specimen. 

 Height, 2 mm. ; breadth, 8 mm. 



May be sought during the months of June to October. 



The Growth is complete by the end of August. 



These galls vary from the size of a mere speck to aggre- 

 gations which cover two-thirds of the area of a leaf They 

 are not common, and appear to be very local ; but where the 

 mites have been long established on a tree, the galls are very 

 numerous. The author once found a twig, 4^ in. long, bearing 

 twelve leaves, nine of which were more or less attacked by 

 the mites. Unfortunately, it was not possible to preserve it 

 for photographing. The illustration on the opposite page is 

 the best procurable at the time of writing the description. 

 It is hoped that it may be some help to the gallist for the 

 purpose of identification. 



The illustration is of specimens gathered at Hastings by the 

 author. 



