30 



FOREST ENTOMOLOGY. 



surface of the leaf. A section of the gall, which is comparatively 



easily made, shows that the walls are very thick. 



There are many other species forming galls on leaves of our forest 



trees and shrubs in many parts of the coun- 

 try, as, for example, on the leaves of the 

 " Wayfaring tree " ( Viburnum lantana), fig. 

 31, which was photographed from a leaf 

 taken in a Surrey lane. 



Species causing Malformation of Flowers, 

 Fruit, or Leaves. 1 



Eriophyes fraxini (Karp). 



This species attacks the flowers of the 

 common ash (Fraximts excelsior), and gives 

 rise to what may popularly be called de- 

 formed fruit, as the injuries are most com- 

 monly observed when the fruit is ripe. It 

 Fig. 31. Galls ion, leaf of Way- j s however, more correctly a malformation 



faring tree (Viburnum lau- J 



tana) caused by Eriophyes f the flower, as the mites attack the flower, 



tetanothnx. ' 7 



and by means of a symbiotic action give 

 rise to the forms as seen in fig. 32. It is very local in some 

 parts of the country, and sometimes peculiarly so to one tree in a 

 whole district. It is very common in some parts of Northumberland 

 and Berwickshire. 



Eriophyes tiliarius (Con.) 



This species attacks the flower-bracts of the common lime (Tilict 

 europcea). Having only found this species once, which was in 

 Northumberland, I give the following note from Connold, 2 who has 

 figured the species : 



" These galls begin to form on the margin of the bract as small 

 elevations. The feeding of the mites causes the edge of the bract to 

 rise upwards and curl over towards the midrib, producing a roll which 

 sometimes extends 30 to 40 mm. in length, and continues to roll 



1 For a full and interesting account of "Gall-Mites" under similar classification 

 to the above, see 'Die Krankheiten der Pflanzen,' Frank, vol. iii., 1896. 



2 British Vegetable Galls, p. 170. 



