386 INSECTS INJURIOUS TO VEGETATION. 



these insects should be able to get any nourishment from wax, 

 a substance which other animals cannot digest at all; but they 

 are created with an appetite for it, and with such extraordinary 

 powers of digestion, that they thrive well upon this kind of 

 food. As soon as they are hatched they begin to spin; and 

 each one makes for itself a tough silken tube, wherein it can 

 easily turn around and move backwards or forwards at pleasure. 

 During the day they remain concealed in their silken tubes ; 

 but at night, when the bees cannot see them, they come partly 

 out, and devour the wax within their reach. As they increase 

 in size, they lengthen and enlarge their dwellings, and cover 

 them on the outside with a coating of grains of wax mixed 

 with their own castings, which resemble gunpowder. Pro- 

 tected by this coating from the stings of the bees, they work 

 their way through the combs, gnaw them to pieces, and fill 

 the hive with their filthy webs ; till at last the discouraged 

 bees, whose diligence and skill are of no more use to them in 

 contending with their unseen foes, than their superior size and 

 powerful weapons, are compelled to abandon their perishing 

 brood and their wasted stores, and leave the desolated hive 

 to the sole possession of the miserable spoilers. These cater- 

 pillars grow to the length of an inch or a little more, and come 

 to their full size in about three weeks. They then spin their 

 cocoons, which are strong silken pods, of an oblong oval shape, 

 and about one inch in length, and are often clustered together 

 in great numbers in the top of the hive. Some time after- 

 wards, the insects in these cocoons change to chrysalids of a 

 light brown color, rough on the back, and with an elevated 

 dark brown line upon it from one end to the other. When this 

 transformation happens in the autumn, the insects remain 

 without further change till the spring, and then burst open 

 their cocoons, and come forth with wings. Those which 

 become chrysalids in the early part of summer are transformed 

 to winged moths fourteen days afterwards, and immediately 

 pair, lay their eggs, and die. 



Bees suffer most from the depredations of these insects in 

 hot and dry summers. Strong and healthy swarms, provided 

 with a constant supply of food near home, more often escape 



