Galls caused by the larvje, nymphs, and imagines of 

 Eriophyes tristratus, var. erinea Nal. 



on 



the leaves of Juglans regia Linn. 



PLATE 70. 



Synonymy of Mite. 



Erineum jiiglandinuni Pers., Murray. 



I. juglattdis Ung. 

 Phyllerium juglattdis Schl. 

 Phytoptus tristratus, var. erinea Nal. 



Habitat of the Walnut-tree. — It is well distributed 

 throughout Britain in private grounds and parks, and 

 also on farms. 



Position of the Galls. — On the leaflets, in the areas en- 

 closed between the primary and secondary offshoots from 

 the mid-rib. 



Manner of Growth. — Singly or in numbers ; glabrous on 

 upper surface, pubescent on under surface. 



Colour. — Greenish yellow, suffused with reddish brown. 



Average Dimensions of a Mature Specimen. 

 Height, 5 mm. ; length, i6 mm. ; breadth, lo mm. 



May be sought during the months of June to October. 



The Growth is complete by the end of August. 



The presence of the mites on the under surface of the leaf 

 is first shown by the growth of pale yellow hairs on the parallel 

 secondary offshoots from the mid-rib. The area which they 

 enclose then becomes pilose, and at the same time a slight 

 discoloration and elevation of the upper surface is noticeable. 

 The deformities increase until a convexo-concave swelling is 

 produced, the interior of which is filled with a thick felt of 

 pubescence of a pale buff colour. See also plate 75. 



The illustration is of specimens gathered at Guestling, near 

 Hastings, by the author. 



172 



