TREE INSECTS AND THEIR CONTROL 213 



openings that the caterpillars, when 

 hatched, enter the wood to begin their 

 work. Wounds and scars are a constant 

 invitation to this insect, and its preference 

 for such injuries is a strong argument for 

 protecting trees from injury and the care- 

 ful dressing and treatment of wounds. 

 The insect lives for about three years, and 

 spends almost the entire time eating into 

 and feeding on the heart-wood. The 

 burrow may be half an inch in width, and 

 will cause the wilting of twigs and unsat- 

 isfactory growth. 



Egg-laying occurs early in the summer, 

 and, soon after hatching, the caterpillar 

 burrows into the heart-wood. When the 

 insect emerges, after three years of dam- 

 age, it is in the form of the adult moth. 



occur and that such injuries as may come 

 are carefully and promptly cleaned and 

 dressed with tar or paint. (Page 145). 



When a tree becomes infested, winter is 

 the time for destroying the worm. Dur- 

 ing that season all infested wood should be 

 cut away and burned. Into the wounds 

 caused by the cutting and the tunneling, 

 carbon disulphid should be injected as 

 an added measure of control, and the 

 wounds should immediately be plugged 

 and sealed with soap, grafting-wax, clay 

 or putty. 



Maple and Oak Twig Pruner 



Habits This enemy specializes on 



and the Maple and the Oak, and 



Damage, while it does not kill the trees 

 it impairs their looks by sever- 

 ing twigs and causing them to fall to the 

 ground or hang to branches. The grub 

 passes the winter in the severed twig, 

 emerging in June as a pupa or chrysalis. 

 In July the parent beetle lays its eggs on 

 small twigs and, upon hatching, the grubs 

 begin at once to feed on the wood, making 

 tunnels which sever the twigs. During 

 the summer the ground is covered with 

 twigs cleanly cut off, as with a saw. In 

 the center of each twig is a burrow, filled 

 with debris, and in this burrow will usu- 

 ally be found a white grub with brown 

 jaws. Many twigs almost severed will be 

 seen hanging from the tree. Damage to 

 the shape of the tree is the most serious 

 result. 



SAP-SUCKING INSECTS 

 Oyster-shell Scale 



(See description and remedies under Elm) 

 Cottony Maple Scale 



Remedies. Since the insects remain 

 in the severed ends, the best 

 remedy is to gather and burn the fallen 

 and hanging twigs. This should be done 

 before June, the time for the adult beetles 

 to leave the twigs in which the winter has 

 been spent. Action at this time will pre- 

 vent the laying of eggs for the production 

 of a new brood. 



Habits Considerable damage some- 



and times results from the attack 



Damage, of this insect. The presence 

 of the scale is first noticeable 

 in June, when the body of the adult female 



Remedies. It is not always necessary 

 to apply remedies, but if 

 needed, a spraying with dilute kerosene 

 emulsion, summer strength, is effectual if 

 used during the hatching season. Brush- 



