7o6 



TREES AS GOOD CITIZENS 



in the bark. The damage to a tree shows 

 itself first in leaves turning brown at the 

 ends of infested branches, then by the 

 death of branches and finally in the death 

 of the tree. In dying trees, the bark on 

 trunk and larger branches may be easily 

 peeled off in patches, and underneath 

 these the grubs are found. 



Leopard Moth 



Habits This moth takes its name 



and from the leopard-like spots on 



Damage, its white wings. The adult 

 moth lays eggs in crevices of 

 the rough bark, a single specimen some- 

 times depositing 700 or 800 eggs. The 

 larvae, or grubs, hatch within 10 days and 

 at once begin their destructive work of 

 feeding on the wood, boring toward the 

 heart of the tree as they feed. Twigs 

 infested break off, the bark splits and 

 forms ugly scars, and chips and matted 

 discharges are found at the entrance to 

 the burrow. The grubs' period of activity 

 continues for two years, serious damage 

 is caused and frequently the death of the 

 tree results from girdling of the trunk. In 

 about two years the grub changes into a 

 chrysalis and then into a moth, and egg- 

 laying follows. Even when the attack is 

 not so severe as to cause death, the 

 growth of a tree is seriously hampered. 



Because of this borer's tendency to migrate from tree to tree, 

 cooperative work is always necessary. 



Treatment. The control of this insect 

 is difficult. When a tree or 

 limb has become badly infested before 

 discovery of the attack, the only recourse 

 is to cut and burn the infested part 

 immediately, even if this involves cutting 

 down the tree itself. This drastic action 

 is necessary to prevent the spread of the 

 pest to other trees. In cutting and burn- 

 ing, care should be exercised, and prompt 

 action employed, to keep the borers from 

 escaping and migrating. 



If a tree shows a few burrows, it is some- 

 times possible to arrest the damage by 

 injecting carbon disulphid into the chan- 

 nels. This kills the borers. In some cases 

 the borers may be killed bodily by prob- 

 ing with a flexible wire inserted into the 

 channel. Action should always be immedi- 

 ate when the borer's presence is detected. 



community or 



Twig Girdler 



Habits 



and 



Damage 



hanging. 



The pet habit of this insect 

 is to destroy twigs and bran- 

 ches by girdling them until 

 they fall off, or die and remain 

 The girdler appears in late 

 summer or early fall and is apt to feed 

 on the thin bark of twigs before laying 

 eggs. The female attacks twigs from % 

 to \yi inches in diameter, and cuts rings 

 around them deep into the wood; the eggs 

 are laid in openings cut through the bark. 

 It is these wounds that cause the twig to 

 die. After the eggs are hatched the grubs 

 feed on the wood for a year or more. 

 Examination of the burrow in a fallen 



Treatment. There is no remedy for 

 this insect pest, but it con- 

 tributes to its own destruction by remain- 

 ing in the falling or broken twig. It is 

 important to gather and burn the twigs 

 as soon as they fall or break, for the pur- 

 pose of destroying the girdlers. This is 

 the only treatment to be given. Nature 

 helps in destroying the pest by letting 

 them overcrowd each other in the individ- 

 ual twig. 



