Galls caused by the larvae, nymphs, and imagines of 

 Eriophyes pustulatum 



the leaves of Populus tremula Linn. 



PLATE 61. 

 Synonymy of Mite. 



Habitat of the Aspen. — This tree grows well in coppices, 

 woods, and forests. It may also frequently be seen in 

 profusion on the outskirts of a wood by the side of a 

 stream. 



Position of the Gall. — Projecting from the upper and 

 under surfaces of the leaf 



Manner of Growth. — Separate; sessile; glabrous; glossy. 



Colour.— Greenish yellow, orange-yellow, red, purple. 



Average Dimensions of a Mature Specimen. 

 Height, 2 mm. ; girth, 5 mm. 



May be sought during the months of June to October. 



The GrO\vth is complete by the end of August. 



These galls appear to be very local, and nowhere abundant. 

 About equal proportions of the gall project from each surface 

 of the leaf There are seldom more than four or five galls on 

 an average-sized leaf Two leaves on the right-hand side of 

 the illustration show the under surface and the little hole in 

 each gall through which the Eriophyes leave and enter the 

 swelling. Unfortunately our illustration does not do fullest 

 ju-;tice to these very pretty and interesting little galls. 



The illustration is of specimens gathered at Hastings by the 

 author. 



