INSECTS, DISEASES, AND INJURIES 125 



Ohio, and southward are subject to attack by the larva of a 

 moth which protects itself by a silken bag into which are 

 incorporated bits of leaves and small twigs. The larva remains 

 in this bag throughout its entire feeding period and carries the 

 bag with it wherever it goes. It protrudes the head and front 

 part of the body when moving about or feeding. The young 

 larvae appear in May or June and maturity is reached in the 

 fall. The female moth is wingless and does not leave the bag 

 till after she has deposited her eggs. The bag containing the 

 eggs remains on the tree throughout the winter firmly attached 

 to the twig by a band of silk. In this way the twigs are often 

 girdled and killed. ^Tien abundant, defoliation may be severe 

 and the trees stunted and killed. 



The bag-worm may be controlled effectively by spraying 

 with arsenate of lead, three pounds of powder in one hundred 

 gallons of water, as soon as the larvae have all hatched, that 

 is, some time early in June. In case only a few trees are 

 affected, hand-picking the bags in the fall or early spring 

 is an effective measure. 



The gipsy moth {Porthetria dispar, L.). Figs. 8, 9. 



The gipsy moth is a serious forest and shade-tree pest 

 throughout the greater part of New England. It is a European 

 insect and was introduced into eastern Massachusetts in 

 1869 where it has become a much more serious pest than in 

 its native home. The winter is spent in the egg state. The egg 

 masses are oval in outline, light brown in color, covered with 

 hairs from the moth's body, and are placed on trunks of trees 

 or in any sheltered place. The eggs hatch in the spring just 

 as the buds are bursting, and the caterpillars feed on the tender 

 foliage. The young caterpillars are not able to feed on the 

 leaves of pine, but the older ones thrive on this food plant. 



