INSECTS 207 



Nymph is a name given to the larval stage of dragon flies, 

 stone flies, grasshoppers, and some others having incomplete 

 life changes. 



Exercise. — Collecting Caterpillars. — Late in fall let 

 pupils bring to school caterpillars or other larvae of several 

 kinds which they may find. Let these be placed in boxes 

 with wire or cloth gauze tied over them. Place in the bot- 

 tom of the box some soil and insert in this some of the twigs 

 with leaves for the larvae to feed upon. If the caterpillars 

 are found on plants, that will indicate what food they pre- 

 fer. If they form pupa cases in the cage, these may be kept 

 in a cool place until the warm weather of spring brings them 

 out. Or they may be induced to transform to the adult 

 stage by bringing them into a warm room for a few weeks 

 in February or March. 



Exercise. — Collecting Cocoons. — Cocoons and pupa may 

 be collected during the wdnter months and brought to school, 

 where the transformations may be watched. 



Exercise. — Making Glass Cages for Insects. — Let the 

 pupils bring a few tin cans or six-inch flower pots, some 

 large glass chimneys, such as lamp or lantern chimneys, 

 and cloth netting. Damp soil may be kept in the pots and 

 the chimneys placed over them with gauze tied on the top 

 of the chimneys (Fig. 124). The cages may be used at school 

 for insects that are to be observed by the pupils. Suitable 

 plants may be kept fresh by inserting the stems in a small 

 bottle of water inside the cage. 



Insect Enemies of Man. — Among the many kinds of 

 insects there are those that are beneficial and others that 

 are injurious. Some of the injurious insects are found 

 attacking man himself; others his prepared food and cloth- 

 ing; and others harass the domestic animals, or attack the 

 crops in the field, garden, or orchard. 



Mosquitoes. — Mosquitoes are not only troublesome 

 pests; they are worse than that, because they are carriers 



