548 Animal Biology 



nectar and pollen from various flowers they carry pollen from one flower 

 to another, thus ensuring the pollination necessary for fruit and seed 

 formation. Certain insects act as scavengers by destroying dead animals 

 and plants. Others bury dung and carcasses. All of these cause these 

 dead materials to be reverted to the soil where they can be utilized 

 again by future plants. 



Certain insects also serve as food for other animals which are valu- 

 able for us. Many game and song birds depend for the most part on 

 insects for their natural diet. Many of our fishes use aquatic insects 

 as foods. The large numbers of May flics which occur in fresh water 

 at certain periods of the year are used in great quantities for this pur- 

 pose. Racoons, skunks, and other wild, fur-bearing animals eat insects. 



In many parts of the world such insects as crickets, grasshoppers, 

 beetles, termites, aquatic bugs, bee larvae and pupae, and caterpillars 

 are used as food by the more primitive races of men. 



Insects promote soil fertility and improve soil conditions by serving 

 as fertilizer and by burrowing throughout its layers, thus permitting air 

 and moisture to penetrate to the roots of plants. Insects also destroy 

 great numbers of weeds which might be harmful or at least take the 

 nourishment away from more desirable plants. In this way insects are 

 beneficial to man in helping him keep weeds somewhat under control. 



Insects also have certain aesthetic values, because their colors, shapes, 

 and patterns serve as models for decorators, artists, and milliners. The 

 highly colored types are used for such ornaments as pins, necklaces, 

 jewelry, and trays. They serve as subject matter and inspiration for 

 poetry. The Oriental peoples train certain types of crickets for sport 

 purposes. Fleas are trained for performances in flea circuses, not only 

 for amusement but for financial reasons. Last but not least, insects 

 aff'ord much diversion and entertainment for the many amateurs who 

 collect and studv them. 



Many types of insects are beneficial to man because they destroy 

 other injurious types by capturing and devouring them. Many kinds 

 live as parasites in or on the bodies of other more harmful types. 



Scientific investigations of great value to man have been based on the 

 study of insects. A study of the fruit fly or banana fly (Drosophila) 

 has aided man materially in his study of heredity (Fig. 332). The 

 psychology and behavior of higher animals frequently have been illumi- 

 nated by a study of the simple tropisms and reactions of insects. 



A study of coloration in insects undoubtedly has influenced the science 

 of camouflage. It is a possibility that insect coloration may have sug- 

 gested the idea of artificial camouflage in the beginning. 



