Galls caused by the larvae, nymphs, and imagines of 

 Eriophyes macrochelus Nal. 



on 



the leaves of Acer campestre Linn. 



PLATE 5G. 



Synonymy of Mite. 



Erineuni purpurascens Gaertn. 



Phyt Optus moniezi Fock. 

 „ macrocJielus Nal. 



Cephaloneon solitariu7n Bremi. 

 Habitat of the Common Maple. — Abundant in southern 



England, but less plentiful in the north and in Scotland. It 



is found in woods and hedges, the latter situation being the 



favourite. 

 Position of the Galls. — On the upper surface of the leaf 

 Manner of Growth. — Usually gregarious ; globular, ovid, 



and reniform in shape. 

 Colour. — Green, orange-yellow, red, brown. 

 Average Dimensions of a Mature Specimen (reniform 

 shape). 



Height, 4 mm. ; length, 6 mm. ; breadth, 3 mm. 

 May be sought during the months of June to November. 

 The Growth is complete by the end of August. 



These galls are exceedingly variable in many ways. They 

 may be solitary or coalesced, gregarious or single, sessile or 

 semipedunculated, glabrous or pubescent, glossy or dull, and 

 triplicate in shape. They are larger and not so numerous as 

 those caused by E. macrorhyncus, and they are more confined to 

 the primary offshoots from the petiole. Occasionally they de- 

 velop on the under surface of the leaf The cell-walls are very 

 thick and woody. A leaf of average size may have from fifty 

 to two hundred galls upon it without causing any distortion. 

 Some leaves are entirely covered with them : the deformity is 

 then very great. 



The gall is also figured by Nalepa, " Neue Gallmilben," 

 Taf XV. 



The illustration is of specimens gathered at Hastings by 

 the author. 



144 



