THE ECONOMIC STATUS OF INSECTS AS A CLASS. 1 



By L. O. Howard. 



The popular conception of insects in general is undoubtedly that they 

 are injurious. Many writers, it is true, have pointed out the benefits 

 derived from insects, but we think of their damage to crops aud of 

 their annoyance to man and animals, and this aspect of the subject is 

 at once apt to preponderate in our minds. It is more than eighty years 

 since Kirby and Spence contrasted the injuries caused by insects with 

 the benefits derived from them, and it has not been comprehensively 

 done since. In the meantime, whole groups of important injuries have 

 been developed and whole classes of beneficial work have been discov- 

 ered. Moreover, the tendency of modern thought has not taken this 

 direction. The biologic, taxonomic and phylogenetic, and other aspects 

 of large groups of forms of life have been considered to the exclusion 

 of the economic aspect, and even where this side has attracted attention 

 investigators have confined themselves to specific problems and have 

 not generalized. It may be interesting, therefore, once more to con- 

 trast the injurious insects with the beneficial ones in an effort to gain 

 a clearer idea of the status of the group in its relations with man. 



In a broad way, we may consider the subject under the following- 

 heads : 



Insects are injurious: 



1. As destroyers of crops and other valuable plant life. 



2. As destroyers of stored foods, dwellings, clothes, books, etc. 



3. As injuring live stock and other useful animals. 



4. As annoying man. 



5. As carriers of disease. 

 Insects are beneficial : 



1. As destroyers of injurious insects. 



2. As destroyers of noxious plants. 



3. As pollenizers of plants. 



4. As scavengers. 



5. As makers of soil. 



6. As food (both for man and for poultry, song birds, and food fishes) 

 aud as clothing, and as used in the arts. 



1 Address of the retiring president of the Biological Society of Washington, deliv- 

 ered January 18, 1899. Printed in Science, Vol. IX, No. 216, February 17, 1899. 



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