Ill 



the bark and sapwood deep into the heart-wood, in which it excavates 

 large more or less vertical tunnels. The caterpillar changes to a large 

 brownish pupa which usually projects from the tunnel openings on the 

 surface before disclosing the moth. Its work results in unsightly de- 

 formities on the trunks of the infested trees, and destructive fungi obtain 

 entrance through its burrows. It is a serious enemy in Eastern Canada 

 to ash, maple and black locust trees, and has been recorded also from 

 willows, poplar, oak, elms and chestnut. 



Control Measures. — The control of this insect is difficult. The 

 best practice appears to be to trim away the roughest portions of the 

 deformities, and then inject a sufficient amount of carbon sulphide into 

 the borings with a syringe, and close the holes with putty or cement. 



The Maple Sesian, Sesia acerni, is injurious to maples. The adult, 

 a beautiful, wasp-like moth, desposits its eggs commonly about wounds 

 on the trunk. The caterpillars are often found boring in the developing 

 wound tissue. Large unsightly wounds and greatly weakened trees result 

 from their work. 



Control Measures. — Wounds resulting from any cause should be 

 properly trimmed and coated with tar or grafting weix as soon as discovered. 

 Infested trunks should be examined late in the season, the borers removed, 

 the wounds properly smoothed and covered with tar. 



The Sugar Maple Borer, Plagionotus speciosus, is a rather common 

 enemy of Sugar maples in Quebec Province. The injury caused by the 

 borers is often seen. The adult, a beautiful black and yellow beetle about 

 an inch long, deposits its eggs in midsummer in slits in the bark of the 

 trunk or larger branches. The legless grubs have powerful jaws and 

 excavate shallow burrows, often several feet long, in the inner bark and 

 sapwood. These tunnels more or less completely girdle and seriously 

 weaken or kill the infested branches or trunks. The young grubs are 

 betrayed in the fall by protruding "sawdust" and the tunnels of the larger 

 borers produce unsightly scars. The grub changes to the pupa and the 

 latter to the adult beetle in the end of the tunnel, and the beetles cut their 

 way out through the bark by an oval hole about one-half inch in diameter. 

 The beetles appear in June and July to deposit their eggs for the next 

 brood. Apparently healthy trees are attacked, and dying branches and 

 trunks as well as the scars referred to are the result of its work. 



Control Measures. — Much of the injury could be averted by ex- 

 amining the trees in the fall and again in the spring and cutting out the 



