ENGLISH: ILLINOIS TREES: THEIR INSECT ENEMIES 



35 



HACKBERRY 



Hackberry Nipple Gall Psyllid, Pachypsylla celtidismamma 

 (Riley). —Conspicuous growths on the under sides of hackberry 

 leaves are signs of an infestation of this insect, sometimes called 



Fig. 27.— Witches'-brooms on a hackberry tree. The brooms are very 

 conspicuous in winter, when no leaves are on the tree. 



