APPLE INSECTS — BUDS AND FOLIAGE 



119 



The Forest Tent-caterpillar 



Malacosoma disstria Hiibner 



The common name of this species is a misnomer, for the cater- 

 pillars do not construct a true tent, as in the case of the pre- 

 ceding species. It is closely related to the apple-tree tent- 

 caterpillar, and has a similar life history, but its habits are 

 decidedly different. Its range extends throughout the United 

 States and Canada and it has been reported from Mexico. It 

 is naturally a forest in- 

 sect, the maple being 

 its favorite food plant. 

 When unusually abun- 

 dant, however, it attacks 

 a large number of trees 

 and shrubs, and in the 

 orchard feeds on the 



apple, plum, peach, Fig. 129. — Egg-rings of the forest tent-cater- 



cherry and pear. Severe pillar, 



outbreaks occur at 



rather long intervals and usually last for only two or three 

 years. In 1898 and 1899 a very extensive and severe outbreak 

 occurred in New York and New England ; the caterpillars de- 

 foliated thousands of acres of forest and did great damage in 

 fruit orchards. They also appeared in destructive numbers 

 in 1912 and 1913. 



The winter is passed in the egg stage (Fig. 129). The eggs 

 hatch in early spring and the young caterpillars feed in colonies 

 on the opening heaves. They leave a silken thread wherever 

 they go and in this way the colony frequently webs in some of 

 the leaves where they are feeding. These slight webs are not 

 true tents ; they are n(;ver entered by the caterpillars and are 

 not used for protection. When not feeding or when preparing 



