200 



THE MONTHLY BULLETIN. 



white threads of wax (Fig. 208). Besides the coverings they are pro- 

 tected by offensive secretions and are not generally preyed upon by 

 insectivorous animals. During their growth they moult four times 

 and when fully matured seek shelter to pupate. 



Pupae or Nymphs. — The larvte not having a waxy or exceedingly 

 hairy or spiny covering, usually hang by the tail and pupate with the 

 head downward (Fig. 189D), while the covered ones pupate within 

 the larval skins which give ample protection. Offensive liquids are 



Fig. 1S5. — Two species of CocchielUdw (Hippodamia convergens Guer. and H. ambigua 

 Lee.) emerging from hibernating quarters in tlie spring. (After Carnes. ) 



also secreted for protective purposes. The naked nymphs have the 

 ability to move the suspended body very rapidly when disturbed. 



Adults.— The adult beetles emerge through slits in the pupal skins. 

 Ttiey are exceedingly active, feeding throughout their existence. In 

 size they vary from one sixteenth to nearly one half inch in length. 

 The color is usually showy and of many shades and combinations. The 

 males are somewhat smaller than the females and sometimes with 

 slightly different colorations. The winter is passed in hibernation. 

 In some species thousands of individuals collect in the mountains in 

 great colonies. With the first warm spring weather these emerge from 

 the winter quarters and migrate to the lower valleys and disperse to 

 give rise to succeeding generations. 



