ENGLISH: ILLINOIS TREES: THEIR INSECT ENEMIES 



39 



branches, weakening many of them so that they bend down, 



break, and die. 



Control Measure 13 (end of circular) at monthly intervals 

 during the spring and summer, beginning about April 15. If 

 mites develop, Control Measure 9 also should be used. 



Spruce Spider Mite.— See under Spruce. Control Measure 

 9 (end of circular). 



Bagworm, fig. 2.— See under Arborvitae. Control Measure 

 1,3, 11, or 21 (end of circular) in June, while worms are small. 



Fig 29.— Juniper webworm: larva (inset) and web on damaged branch. 

 A colony of the small, brown caterpillars of this insect usually kills an in- 

 fested branch. 



