90 



ARTHROPOD A 



almost invisible eggs on the bark of stone-fruit trees near 

 the ground. The white larva bores into the tree, feeding 

 on the sap wood near or below the surface of the ground, 

 and making its presence known by the exudation of gum 

 and fragments of borings about the base of the tree. By 

 late autumn it is almost an inch long, and it then remains 

 dormant until the following spring. The approach of 

 warm weather again stimulates it to feed a few weeks and 



FIG. 96. Peach, tree borer ; a, female moth ; 6, male moth ; d and e, pupae ; c, lar- 

 , va ;/, chip cocoon with extruded pupa skin. Natural size, after Marlatt. 



in late spring or early summer its transformation to pupa 

 and adult is accomplished witliin a chip and gum cocoon 

 at the base of the tree. 



Metamorphosis among the Lepidoptera is complete, i.e., 

 there are four well-marked stages, the egg, larva, pupa, and 

 imago or adult. In some species the eggs hatch a few 

 hours after being laid, while in others they remain over 

 winter. The larva of most species, except those of the 

 measuring worms, have eight pairs of legs of which the 

 three anterior are known as true legs because they become 



