Insect Enemies of Trees 



199 



is brought about by the female aphis piercing with her beak, 

 or sucker, one of the buds, and drawing off the sap, the 

 consequence being an unusual growth at that part. 



When the young larvae appear, they also, by piercing the 



ELM TREE DESTROYER 



A. Entrance of Parent Tube. 



B. Insect in Tube. 



C. An imperfect Tube arrested from want of nourishment. 



D. Scolytus Destructor. Natural size. 



E. Lateral Tubes with Larvae, some changing to the Pupa state. 



gall, extract the juices, and the gall enlarging soon causes 

 the larvae to become embedded at the bases of the leaves, 

 which, by this time, have become curiously malformed. The 

 insects are scarcely one-tenth of an inch long. 



