Galls caused by the larvae, nymphs, and imagines of 

 Eriophyes crataegi. 



on 



the leaves of Crataegus Oxyacantha Linn. 



PLATE 50. 

 Synonymy of Mite. 



Habitat of the Hawthorn.— In woods and thickets through- 

 out Britain ; also forming artificial hedges by the sides of 

 railways, roads, and lanes. 



Position of the Galls.—Oh both surfaces of the leaf. 



Manner of Growth. — Gregarious ; glabrous ; coalescent. 



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



Average Dimensions of a Mature Specimen. 

 Height, 4 mm. ; breadth, 2 mm. 



May be sought during the months of May to November. 



The Growth is complete by the end of September. 



These galls are mostly lenticular in shape, and are fairly 

 evenly distributed on the upper surface, as well as on the under 

 surface of the leaf They are situated on any part except the 

 mid-rib and its primary offshoots, and are usually not very 

 numerous. An average-sized leaf may have about a hundred 

 galls upon it. The number depends very much upon whether 

 the mites have been long established on the plant, which when 

 in a hedge harbours them more effectually than when they 

 affect the leaves of a hawthorn grown to a tree. In the illustra- 

 tion many of the leaves show the under surface. 



The illustration is of specimens gathered at Hastings by the 

 author. 



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