INSECTS 



71 



The cockroaches (Fig. 116), kindred of the grasshoppers, 

 are household pests that have migrated almost everywhere 

 that ships go. The praying mantis (Fig. 117), or devil's 

 horse, also belongs to this order. It is beneficial, since it 

 destroys other insects. Which of its legs are specialized ? 

 The walking stick (Fig. 121) and cricket (Fig. 118), like 

 most members of the order, are vegetarian. 



Are grasshoppers more common in fields and meadows, 

 or in wooded places ? How many different colors have you 

 seen on grasshoppers ? Which 

 colors are most common ? 



Grasshoppers are very scarce 

 in Europe as they love dry, 

 warm countries. Why do lo- 

 custs migrate ? Give an in- 

 stance in ancient times. 



How long do most grass- 

 hoppers live ? Does a grass- 

 hopper spread its wings before 

 it flies ? Does it jump and fly 

 together ? Can it select the 

 place for alighting ? 



Note to Teacher. — Field work in 



r, , u 1 1 u * *■ -c <.„,*.■;*. Fig. 121. — Four Walking Stick 

 Zoology should be systematic. Every trip x 1U - 



1 1 r ■ • 3 j il -l. i- c Insects. 



has a definite region and definite line 01 



study in view, but every animal seen should be noted. The habitat, adapta- 

 tion by structure and habits to the environment, relations to other animals, 

 classification of animals seen, should be some of the ideas guiding the study. 

 The excursions may be divided somewhat as follows, according as opportunities 

 offer: Upland woods, lowland woods, upland pastures, fields, swamps, a fresh- 

 water lake, a pond, lower sea beach, higher sea beach, sand hills along shore, 

 roadside, garden, haunts of birds, insect visits to flowers, ground insects, 

 insects in logs. 



An alphabetical letter file may be used for filing individual field observations. 

 These should be placed before the class orally or in writing. If accepted as 

 reliable (repeated and revised if necessary), the observations should be filed 



