TREES AND SHRUBS 



the leaf. They are hollow, the interior containing a quantity of long hairs, 

 giving shelter to innumerable mites. A single leaf may support as many 

 as 1.50 of these galls. 



The leaves of the Common Maple are often literally covered with smooth, 

 semi-globular pimples, the work of a gall-mite] {JEriophyes macrorhyneus). At 

 first greenish-yellow, the galls pass through shades of yellow, orange-yellow, 

 red, crimson, and purple, and finally become brown. Many leaves will support 

 400-500 galls ; some may even bear as many as 800, and a somewhat large 

 leaf has been crowded with nearly 1400. 



The Maple foliage is also attacked by a somewhat similar, but larger 

 gall, made by the mite Eriopln/es macrochelus. A leaf may have 50-200 

 of these globular galls, which vary considerably in shape and appearance, 

 being usually green, orange-yellow, red, or brown in colour. Occasionally 

 they may be seen on the underside of the leaf, but are most often situated 

 on the upper surface. 



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