GRASSHOPPERS 65 



puc&ets. These hatch out in the spring as tiny wingless grass- 

 hoppers called nymphs. The young insects molt or cast off their 

 hard exoskeleton several times. At each shedding of the " skin " 

 the grasshopper gets larger. Since this molting results in a series 

 of changes in form from the young nymph to an adult with wings, 

 the whole process is called a metamorphosis or change of form. 

 The grasshopper is said to have an incomplete metamorphosis 

 because the changes in form are not great. The nymphs can be 

 recognized in the earliest stages as grasshoppers. 



In the fall most of the adults die, only a few surviving the winter. 

 In the South and West, some grasshoppers have more than one 

 brood in a summer, which makes them more numerous and there- 

 fore more of a pest to the farmers. 



Relatives of the grasshoppers. Among the near relatives of 

 the grasshopper are the brown and black crickets, cockroaches, 

 " waterbugs," katydids, praying mantis, and many others. 



Self-Testing Exercise 



Grasshoppers belong to the order (1) because they have 



wings placed (2) along the back. The mouth parts are fitted 



for (3). The organs of touch in insects are called (4), 



the organ of hearing, the (5), is usually found under the 



(6) . Insects which pass through a series of (7) 



before they (8) adults are said to undergo a (9). 



Insects have to (10) in order to grow larger. 



PROBLEM HI. HOW TO KNOW SOMETHING ABOUT THE 

 STRUCTURE AND LIFE HISTORY OF A BUTTERFLY 



. Laboratory Exercise. Examine a butterfly carefully with a mag- 

 nifying glass. What do you find covering the body and wings? Note 

 that the legs are smaller and weaker than those of the grasshopper. 

 How many pairs do they have? Are they all the same size? Ex- 

 amine a small portion of a wing under a compound microscope. Draw 

 a scale showing how it fits into the membranous wing. What name 

 is given to this order of insects? Why? The mouth parts of the 

 butterfly are modified into a long proboscis, a sucking tube through 

 which the insect sucks nectar from the flowers. 



Practical Exercise 3. Prepare the life histories of several different butter- 

 flies. If possible, use material that you have collected and mounted. 



