INSECTS IN RELATION TO MAN 329 



the beetles, whose feeding-punctures destroy the bolls and cause them to 

 drop. If unchecked, this pest would destroy fully one half the cotton 

 crop, entailing an annual loss of $250,000,000. As it is, the universal 

 adoption of the cultural methods recommended by the Bureau of Ento- 

 mology promises to reduce the damage to a point at which cotton can 

 still be grown at a fair profit. 



An insect often passes readily from a wild plant to a nearly related 

 cultivated species. Thus the Colorado potato beetle passed from the wild 

 species Solanum rostratum to the introduced species, Solanum tuberosum, 

 the potato. Many of our fruit-tree insects feed upon wild, as well as 

 cultivated, species of Rosaceae; the peach borer, a native of this country, 

 probably fed originally upon wild plum or wild cherry. Many of the 

 common scarabaeid larvae known as " white grubs" are native to prairie 

 sod, and attack the roots of various cultivated grasses, including corn, 

 and those of strawberry, potato and other plants. The chinch bug fed 

 originally upon native grasses, but is equally at home on cultivated spe- 

 cies, particularly millet, Hungarian grass, rice, wheat, barley, rye and 

 corn. In fact, the worst corn insects, such as the chinch bug, wire worms, 

 white grubs and cutworms, are species derived from wild grasses. 



Even in the absence of cultivated plants their insect pests continue 

 to sustain themselves upon wild plants, as a rule; the larva of the cod- 

 ling moth, for example, is very common in wild apples and wild haws. 



The Economic Entomologist. To mitigate the tremendous dam- 

 age done by insects, the individual cultivator is almost helpless without 

 expert advice, and the immense agricultural interests of this country have 

 necessitated the development of the economic entomologist, the value of 

 whose services is universally appreciated by the intelligent. 



Almost every State now has one or more economic entomologists, 

 responsible to the State or else to a State Experiment Station, while the 

 general Government attends to general entomological needs in the most 

 comprehensive and thorough manner. 



"It is the special object of the economic entomologist," says Dr. 

 Forbes, "to investigate the conditions under which these enormous losses 

 of the food and labor of the country occur, and to determine, first, 

 whether any of them are in any degree preventable; second, if so, how 

 they are to be prevented with the least possible cost of labor and money; 

 and, third, to estimate as exactly as possible the expenses of such pre- 

 vention, or to furnish the data for such an estimate, in order that each 

 may determine for himself what is for his interest in every case arising. 



"The subject matter of this science is not insects alone, nor plants 

 alone, nor farming alone. One may be a most excellent entomologist 



