298 ANIMAL LIFE 



parent. The larval stage may continue from 

 three days to three years, depending largely 

 on the species but somewhat upon the food 

 and temperature. It is longest in the Coleop- 

 tera and Neuroptera. Before entering the 

 third stage, that of pupa t the larva some- 

 times forms a case of particles of earth, or 

 weaves a cocoon from its silk glands or from 

 hairs of its body (Fig. 75). The deathlike 

 sleep of the pupa continues from a week to a 

 year, depending upon the species. No food 

 is taken and any temperature from twenty 

 degrees below zero to one hundred degrees 

 above does not seem to harm the insect, but 

 the wonderful reorganization of structure 

 necessary to assume the form of the parent 

 does not take place except during mild 

 weather. The adult stage is usually a winged 

 form, which may not live more than a week, 

 as in the case of many moths, or may exist 

 five or six years, as in the case of the queen 

 honey bee. 



Some insects, such as the locusts, grass- 

 hoppers, cicadas, dragon flies, and May flies, 

 do not exhibit any marked difference in form 

 between the larval and pupal states, and are 

 therefore spoken of as having an incomplete 

 metamorphosis (Figs. 7, 140). The young is 

 then usually called ihenymph 



FlG. 335. Metamorphosis of the cicada . . . .. 



as it occurred between 8 P.M. and and Continues active at all 



times. Often the life of the 



