42 



Fig. 27. 



Fig. 28. 



coon is made, the worm will have moved his head to and fro, in order to distribute the silk, 

 about two hundred and fifty-four thousand times." 



" After about half a day's work, the cocoon is so far completed that the worm can 

 hardly be distinguished through the fine texture of the wall ; then a gummy resinous sub- 

 stance, sometimes of a light brown colour, is spread 

 over all the inside of the cocoon. The larva con- 

 tinues to work for four or five days, hardly taking 

 a few minutes of rest, and finally another coating 

 is spun in the interior, when the cocoon is all 

 finished and completely air-tight." The finished 

 cocoon is shown in fig. 27. 



During this process of spinning, the larva, 

 as might be expected, diminishes in size, .which is 

 due mainly to the enormous quantity of silk it 

 has produced. Within two or three days after the com- 

 pletion of the cocoon, the worm sheds its larva skin and 

 enters upon the chrysalis stage of its existence. The 

 chrysalis (see fig. 28) is of a dark chestnut brown colour, its 

 hind segment being armed with a small brush-like cluster of 

 hooks. Through the anterior segments the antennae, and 

 — on a diminutive scale — the wings of the future moth may 

 be clearly seen. In this condition the insect passes the 

 winter, emerging as a moth in the following June. 

 This insect, especially in the larval state, is subject to the attack of many foes. It has 

 been estimated that ninety per cent, and upwards of the larva fall a prey to insectivorous 

 birds ; the thrushes, catbinis and orioles are said to be especially active in this depart- 

 ment. They also have their insect enemies. Besides the ordinary run of spiders, bugs, 

 wasps, &c., they have a special and most dangerous foe in a species of Ichneumon fly, 



known as Ophion macrurum (fig. 29). This active crea- 

 ture may often be seen in summer flying about, search- 

 ing among the leaves of shrubs and trees for her law- 

 ful prey ; having found the object of her search, she 

 watches her opportunity to place cjuickly upon the 

 skin of her victim a small oval white egg. This pro- 

 cess is repeated until some eight or ten eggs are placed, 

 each one securely fastened by a small quantity of a 

 glutinous substance attached to it for this purpose by 

 the Ichneumon. In a few days these eggs hatch, 

 when the tiny worms pierce through the skin of the 

 caterpillar, and commence to feed on the fatty por- 

 tions within. The caterpillar continues to grow, and 

 usually lives long enough to make its cocoon, when it 

 dies ; au'l in the following summer, in place of the 

 moth there issues its enemy, the Ichneumon parasite. 



