98 ANIMALS AND INSECTS 



know so well. But they should understand that any 

 member of that famih^, — frogs, toads, and tree-toads, 

 — are of great help to us in ridding us of harmful insects. 



They should understand, too, that harmful as applied 

 to the insects means harmful to us in our way of living, 

 or to the plants and trees which we cultivate. 



Alany of the animals and insects most harmful and 

 obnoxious to us have been brought here from other regions 

 where they do no harm. For example, the potato-beetle 

 is a native of the Colorado desert. In its natural home it 

 was rather scarce owing to lack of food, but it acquired 

 a great liking for the potato which the pioneers began 

 to plant in the west. As the potato is extensively culti- 

 vated throughout the country, the beetle has followed it 

 and has increased so enormously as to be a menace to 

 this food crop. This, however, was man's fault or mis- 

 fortune. The beetle in its own home, living on the food 

 which nature provided for it there, did no harm. 



The teacher, by such illustrations, should try to make 

 clear to the children man's responsibility in disturbing 

 the equilibrium of the world. 



OPENING TALK 



What is the most beautiful insect we have studied 

 about thus far? Is it the most useful? What is the real 

 use of beautiful things? Who is the mother of the cater- 

 pillar? Can you repeat the verse which says that a sur- 

 prise is waiting for us? 



Some of the moths lay eggs which, when they hatch 

 out into caterpillars, maj'^ do a great deal of harm to trees 

 and plants. There is another creature, not beautiful to 

 look at, which never does any harm at all, but only good, 

 to the plants we like to grow. We will hear his story with 

 that of two other of our humble helpers. 



