FOOD CONSERVATION AND ECONOMIC ENTOMOLOGY. 



R. L. WEBSTER. 



Damage by insects to crops is o-enerally recognized to be of 

 great importance. Not infrequently we see estimates of losses, 

 but even these fail to impress most of us until some widespread 

 in.sect depredation occurs, such as an outbreak of armyworm^, 

 or of white grubs. Several years ago, at the request of Presi- 

 dent Raymond A. Pearson, the writer made the following esti- 

 mate of the annual losses caused by insects in Iowa. 



ESTIMATES OF INJURY TO IOWA CROPS BY INSECTS. 



Corn $20,000,000.00 10 per cent of crop 



Oats 



Winter wheat 



Spring wheat 



Barley 



Rye 



Potatoes 



Hay (tame) 



Alfalfa 



Total $25,994,500.00 



In a consideration of a set of figures of this kind it must be 

 remembered that there is always a certain amount of damage 

 that passes unnoticed. Not infrequently a crop may be injured 

 sufficiently to cause a decrease of 10 per cent in the total yield. 

 Naturally it is impossible to separate entirely losses due to cer- 

 tain other factors, such as unfavorable weather conditions, poor 

 seed, different soil and plant diseases. Moreover, all possible 

 combinations of these factors may exist. 



It is the opinion of the writer that such an estimate is made 

 on a basis eminently fair. AVhen one considers that it is possible, 

 under favorable conditions, to raise 100 bushels of corn to the 

 acre, and that our average yield in Iowa is something consider- 

 ably less than 40 bushels, one may realize that the state is losing 

 greatly through one cause and another. 



In this paper the writer wishes to point out a few of the 

 destructive insects to crops in Iowa and to show how damage 

 by these may be greatly reduced. In the work of an economic 

 entomologist one meets an individual now and then who will 

 throw up his hands when insects are devastating his fields. 



