86 ARTHROPODA 



the body to form a loop as the hind legs are brought for- 

 ward. Of the many species the most injurious ones are 

 the canker worms. There are two kinds. The fall canker 

 worm (Anisopteryx pomclaria) ruins the leaves of the 

 orchards in certain localities in the northern parts of our 

 country during the month of June. The pupal state is 

 passed in the earth within a dense yellow silken cocoon, 



FIG. 89. Photograph of a colony of oak-leaf rollers. One sixth natural size. 



from which the moth comes forth in late autumn to deposit 

 three or four hundred eggs on the limb of a tree. The 

 female moth is wingless, and therefore the pest spreads 

 over new territory slowly'. The' spring canker worm, 

 similar to the fall species, is common in the Mississippi 

 valley and throughout the West. 



Leaf Rollers (Tortricidae). These constitute a family 

 of rather small moths whose larvae often roll up the edges 

 of the leaves and line the interior with silk to form a cocoon. 

 Some species, such as the oak-leaf roller (Caccecia fervidana), 



