Galls caused by the larvae, nymphs, and imagines of 

 Eriophyes piri Nal. 



on 



the leaves of Pyrus communis Linn. 



PLATE 59. 

 Synonymy of Mite. 

 Phytoptus pyri Murr. 

 „ piri Nal. 



„ arianus + Phytoptus cotoneastri + Phytoptus sorbi 



Pgst 

 „ aronim Canest. 



Typhlodromus pyri Scheut. 

 Habitat of the Pear-tree. — Cultivated in orchards and 



gardens throughout Britain. 

 Position of the Gall. — On both surfaces of the leaf. 

 Manner of Growth. — Gregarious; glabrous; coalescent. 

 Colour. — Pale green, reddish, chocolate-brown. 

 Average Dimensions of a Mature Specimen. 



Height, I mm. ; length, 3 mm. ; breadth, 2 mm. 

 May be sought during the months of May to October. 

 The Growth is complete by the end of July. 



Not infrequently a leaf will be completely covered with 

 the small eruptive pustules caused by these mites. The out- 

 line of the leaf is seldom distorted, but the surface is sometimes 

 much wrinkled and blistered by the large number of the galls. 

 The galls are hollow, and the mites gain access through a 

 minute hole, which, with the aid of a lens, may be seen in 

 the under surface of the leaf This disease of the pear leaves 

 appears to be very common throughout the country, and some- 

 times considerable damage is caused to the foliage. 



The gall is also figured by Miss Ormerod, " Orchard and 

 Bush-fruit Insects," p. 127; Murray, "Economic Entomology," 

 P- 359- 



The illustration is of specimens gathered at Guestling, near 

 Hastings, by the Rev. E. N. Bloomfield, M.A., F.E.S. 

 ISO 



