ENGLISH: ILLINOIS TREES: THEIR INSECT ENEMIES 



45 



Maple Bladder-Gall Mite, Vasates quadripedes (Shimer), fig. 

 33. — Unsightly green and reddish growths (galls) on the upper 

 sides of the leaves of soft maple are signs of an infestation of the 

 extremely small mites of this species. The mites overwinter on 

 the bark of trees and in spring migrate to young leaves, where 

 they stimulate the formation of galls, in each of which many 

 mites live and feed. It is doubtful if galls associated with this 

 species cause enough damage to large, vigorous trees to justify 



Fig. 33. — Maple bladder galls on the upper side of a soft maple leaf. 

 Growth of each gall is stimulated by extremely small mites, which live in 

 the gall. This mite apparently causes little damage, except possibly to 

 small trees. (Photograph from Michigan State University.) 



