ELEMENTARY ENTOMOLOGY 



The egg mass is from one half to three fourths of an inch long 

 and forms a grayish-brown, knotlike band around the twig, closely 

 resembling the bark in color. Each mass contains from one hun- 

 dred fifty to two hundred fifty eggs, placed on end, packed closely 

 together, and covered with a layer of light brown, frothy glue, which 

 gives a tough, smooth, glistening surface to the whole mass. The 

 eggs are deposited by the female moths by early midsummer ; 



when fresh the egg mass is 

 white, but in a few days the 

 color darkens. 



Larva, or caterpillar. Dur- 

 ing late summer the little cater- 

 pillars are formed within the 

 eggs, but do not hatch until 

 the next spring. Often they 

 emerge before the leaf buds 

 have expanded sufficiently to 

 furnish any food, in which case 

 they satisfy their appetites with 

 the glutinous covering of the 

 egg mass, spinning over it a 

 thin web. Soon they are able 

 to bore into the swollen buds, 

 when a web is commenced at 

 the nearest crotch. Wild cherry 

 and apple, which are often 

 stripped of their foliage year 

 after year, are the favorite foods, 

 but all the common fruit trees 

 are more or less frequented, and sometimes the common shade trees 

 are attacked and occasionally one is defoliated. The family instinct 

 is very strong with the young caterpillars and all from one egg mass 

 cooperate in spinning the tent which furnishes them shelter at night 

 and during cold or wet weather. The tent is gradually enlarged by 

 new layers of silk, which cover the masses of excreta in the lower 

 layers, the caterpillars living between the outer layers. They com- 

 mence feeding soon after sunrise, but often retire to the nest during 

 the heat of the day, and always seek its shelter during cold days or 



FIG. 74. Partly formed web of the tent 

 caterpillar 



(Photograph by Weed) 



