24 INSECTS AFFECTING VEGETATION 



Some definite means of estimating losses must be assumed, and 

 any effort to scale down these losses by reckoning possible enhance- 

 ment of the market price in view of the conditions just cited would 

 come more in the category of pure guesswork and be open to quite 

 as great objection as the plan adopted. As an offset to possibly en- 

 hanced values due to shrinkages occasioned by insects, moreover, 

 are certain very legitimate items of cost. A very considerable item 

 of loss properly chargeable to insects is the annual expenditure de- 

 voted to their control, which, except in the case of certain fruit and 

 truck crops, has not been considered in the estimates. This amounts 

 to a very considerable percentage of the value of the crop in the 

 case of orchard fruits, truck crops, and such field crops as cotton 

 and tobacco. In the case of the cereals, protection is chiefly secured 

 by farm practices, such as rotation of crops, variations in the time of 

 planting, etc., and this also applies, to some extent, to cotton, to- 

 bacco, and truck crops. In estimating the losses due to the cod- 

 ling moth, for illustration, it is shown that over $8,000,000 a year 

 is expended in spraying apple trees, allowing a cost of only 5 cents 

 per tree. In the case of citrus fruits the cost of gassing and spray- 

 ing ranges from 5 cents to $1.50 per tree. 



Another legitimate class of losses not included in the estimate 

 is the secondary losses which necessarily result from diminished 

 products. For example, the excessive reduction in winter wheat 

 through the Hessian fly ravages in 1900 put a serious check upon 

 milling operations throughout the region worst affected and caused 

 very heavy loss in this field of industry. Similarly a shortage of 

 cotton may so increase the values as to lead to the shutting down of 

 cotton mills. A shortage of grains means a corresponding loss to 

 the railroads and other transportation companies and to shippers. 

 In other words, any material shrinkage in an important product 

 starts a train of losses to the end of the chapter, the total amount of 

 which is quite beyond calculation or estimate. 



It is believed that these omitted items of loss will make good 

 any difference of price which might result from the larger crops if 

 insect damage were entirely eliminated. Outside of the cash value 

 of the crop, furthermore, is the actual material loss in products, 

 which is absolute so far as the consumer is concerned. The im- 

 portance of this loss will vary with the nature of the crop. With 

 perishable products, such as fresh fruits and vegetables, the losses 

 due to insects may be of minor importance. For example, if the 

 apple crop were increased by 25 or 50 per cent of marketable fruit, 

 values would probably shrink a corresponding amount, and the de- 

 mands of consumption and the possibilities of storage be very greatly 

 exceeded, so that there would actually be very little benefit, if any, 

 to the producer. On the other hand, in the case of staple products 

 of long keeping quality, as grains, cotton, sugar, lumber products, 

 etc., the loss may be reckoned as more nearly complete, and the 

 chief loss due to insects falls in this latter class. 



