234 APPLIED ENTOMOLOGY 



leases the insect from the brown outer pupa skin, and either before or 

 after this, an opening in the cocoon is made and the adult emerges. 

 It then crawls up on something and remains quiet for a while; its wings 

 being free to expand, increase rapidly till of their full size; the surplus 

 fluids in the body are expelled, and after an hour or two the insect is 

 ready for flight. 



While for most Lepidoptera this outline of development is in general 

 correct, in the butterflies we find that cocoon making is limited to attach- 

 ing the hinder end of the body by silk, to the object on which it is to 

 pupate, and the formation of a silken loop around its body to hold it up. 

 Such a pupa, producing a butterfly, is usually given the special name 

 " chrysalis." (See Fig. 317/). 



Besides the names " butterflies" (Rhopalocera), and " moths" 

 (Heterocera) used to distinguish different sections of the Lepidoptera, 

 we also have the terms "Microlepidoptera" or small moths, and "Macro- 

 lepidoptera" or large ones. These are wholly relative and rather indefi- 

 nite, but are nevertheless convenient in spite of the fact that it would be 

 doubtful under which head to designate many species of the order. 



The latest list of the insects of this order found in North America 

 places them in about 70 families, but there are more of these divi- 

 sions in other parts of the world. Some of the families include many 

 species and insects of much economic importance, while others have 

 only a very few. Only the more important families, either in size or 

 because of the pests they contain, are included here. 



Family Cossidae (Carpenter Moths). The larvae of the moths belonging in 

 this family bore in trees and are sometimes quite injurious. There are several 

 native species, the most common being the Carpenter Worm or Goat Moth 

 (Prionoxystus robinics Peck) which lays its eggs in the crevices of the bark of 

 various trees. The larva? bore in the limbs injuring or killing them, and the 

 entire life history is believed to take 3 years. The adults which appear in June 

 and July are quite large, the wings of the female spreading about three, and those 

 of the male about two inches. The wings are mottled light and dark gray, except 

 the hind wings of the male which are yellow. The Leopard Moth ( Zeuzera 

 pyrina L.), a European pest belonging in this family, reached this country before 

 1879 and now occurs along the Atlantic Coast from New Hampshire to Delaware 

 and a rather short distance inland. The wings of the moths (Fig. 228) spread from 

 one to about two inches and are white with numerous black spots. The thorax 

 has seven black spots above. The moths appear from May till September and lay 

 their eggs on the bark, several hundred in all, but usually only a few at a place. 

 The caterpillars (Fig. 229) are liable to enter the small twigs, but may enter else- 

 where, and bore through the wood. Small twigs are killed and larger ones weak- 

 ened and in time may also be destroyed by this boring, and if the branch becomes 

 too small at any time for the larva, it will leave it for a larger one. Injured 

 limbs are often so weakened as to break off during storms. The borer feeds during 

 parls of three seasons, pupating in its burrow the third spring. It is more 

 abundant in and near cities and towns than in the open country 



