ATTACKING THE LEAVES. 



49 



live from ten to twelve days when wholly deprived of food ; 

 but severe frost is fatal to them in this tender condition, and 

 multitudes of them sometimes perish from this cause. These 

 larvae are tent-makers, and soon after birth they begin to con- 

 struct for themselves a shelter by extending sheets of web 

 across the nearest fork of the twig upon which they were 



FIG. 41. 



hatched. As they increase in size, they construct additional 

 layers of silk over those previously made, attaching them to 

 the neighboring twigs, and leaving between the layers space 

 enough for the caterpillars to pass. The tent or nest when 

 completed is irregular in form, about eight or ten inches in 

 diameter, and the holes through which the caterpillars enter 

 are situated near the extremities or angles of the nest, and into 

 this they retreat at night or in stormy weather, also at other 



