THE INSECT PKOBLKM 19 



list of important products. Many insects are of great value to 

 man indirectly, because they destroy other insects. The great- 

 est service, however, which they perform in nature consists in 

 effecting cross-pollination of flowers, and many of our most 

 valuable fruits and flowers would be infertile without their 

 aid. Fortunately the honeybee is the most valuable insect for 

 this work. 



In contrast to the value of these few insects, however, is 

 the great injury done by others in their attacks upon man and 

 animals, causing annoyance, suffering, and often disease. The 

 majority feed upon plants and thus compete with man, directly 

 or indirectly, for the vegetable food supply of the world. Re- 

 cent estimates of the Department of Agriculture divide this 

 damage as follows : 



ANNUAL Loss OF AGRICULTURAL PRODUCTS CAUSED BY INSECTS 

 IN UNITED STATES 



Cereals $23 7,800,000 



Hay .......... ..." 66,000,000 



Cotton ............ 67,500,000 



Tobacco 6,900,000 



Truck crops . 68,000,000 



Sugars 6,400,000 



Fruits ............ 66,000,000 



Farm Forests 15,000,000 



Miscellaneous crops 18,900,000 



Animal products 267,000,000 



Natural forest products 130,000,000 



Products in storage 100,000,000 



Total $1,049,500,000 



These estimates are conservative and relate to purely agri- 

 cultural losses. They do not include the damage caused by 

 common household insects, clothes moths, carpet beetles, 

 roaches, ants, and several human parasites, which entail great 

 labor and expense in fighting them. The annual cost of wire 



