Galls caused by the larvae, nymphs, and imagines of 

 Eriophyes avellanae Nalepa 



on 



the leaf-buds of Corylus Avellana Linn. 



PLATE J,7. 



Synonymy of Mite. 



Acarus pseudogallaruin Vail. 



Pliytoptus psetidogallai-uvi Canest, Tar-Tozz. 



„ coryli Murr., Franeuf. 



„ avellancB Nalepa. 



Habitat of the Common Hazel.— Ubiquitous in Britain 

 in woods, thickets, and hedges. 



Position of the Galls.— The leaf-buds themselves con- 

 stitute the galls. 



Manner of Growth. — Singly ; slightly pubescent ; semi- 

 globular, and cone-shaped. 



Colour. — Green, suffused with reddish brown and chocolate- 

 brown. 



Average Dimensions of a Mature Specimen (cone- 

 shape, gathered in February). 

 Height, lo mm.; girth, 21 mm. 



May be sought during any month in the year. 



The Growth is complete by the end of May, 



In reality these galls may be found all the year round, 

 but they are hardly worth gathering during July and August. 

 The mites transfer themselves from the old to the new buds 

 during that time. They completely destroy the growth of 

 the leaves and catkins which otherwise would unfold from 

 the buds. Some bushes in sheltered places are badly attacked, 

 75 per cent, of the buds being occupied with the creatures. 

 A bud may consist of twenty-five to forty leaf-scales, the 

 inner ones being somewhat thickened and woolly in appearance. 



The illustration is of specimens gathered at Hastings by 

 the author. 



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