INSECTS, AND THEIR RELATION TO MAN 173 



//. TJie Larva (Caterpillar) 



Observations. 1. How many pairs of legs are there ? 



2. Note that, besides true segmented legs, there are others, 

 called prop legs. How many pairs of prop legs are there ? 



3. Find the spiracles. How many are there ? 



4. Examine the mouth parts. Look for black objects. 

 Conclusions. 1. How can you tell how much of the body 



is thorax ? 



2. Has an earthworm a thorax ? 



3. How can you tell a larva from a worm ? 



4. Are the mouth parts apparently adapted for biting or for 

 sucking ? 



Note. This is decidedly the eating stage of an insect, and 

 therefore the stage when it does the most damage. 



III. Pupa or Chrysalis Stage 



Note. Some insects construct a case or cocoon for this stage. 

 Observations. 1. To what is the cocoon or chrysalis at- 

 tached ? 



2. How is it fastened in place ? 



3. Of what is it composed ? 



4. What is inside the cover (if a cocoon) ? 

 Conclusions. 1. What made the cocoon ? 



2. What is its use ? 



3. What is the pupa stage of an insect ? 



Observations. 1. Study a pupa which has been removed 

 from its cocoon. 



2. Are the regions of the body distinct ? 



3. ' Identify by the markings on the shell, the wings, legs, 

 antennae, and spiracles. 



4. Is a live pupa provided with any means of loco- 

 motion ? 



Conclusions. 1. Into what does a pupa develop ? 

 2. Is this stage commonly an active or quiescent one ? 

 What seems to be its purpose ? 



