13 



It has been pointed out by Doctor Howard, and possibly others, 

 that widespread injury, such as that from the Hessian fly or the 

 chinch bug, while undoubtedly resulting in a great diminution in the 

 outjDut of the crop attacked, does not represent a corresponding loss 

 in money to the groAvers, for the resulting scarcity of the commodity 

 brings about an increased valuation which may really leave the farmer 

 little, if any, the worse off financially. Taking this into account, 

 present-day estimates of insect injuries may, on the whole, be too 

 high, but it shoidd be noted that the burden is simply transferred to 

 the consumer, who pays the farmer, or more often the speculator, for 

 the ravages suffered. 



Present resources in the Avays and means of reducing insect rav- 

 ages place a much greater responsibility on the farmer, fruit grower, 

 and others subject to injury than heretofore. In the case of many 

 of our i)rominently injurious species their life histories have been 

 worked out, their most vulnerable points of attack shown, and appro- 

 priate means for reaching them indicated. A mere list of the various 

 insecticides and mechanical methods employed in insect warfare 

 would require more time than is here available and would serve no 

 useful purpose, for the tendency at the present time is mainly toward 

 the use of certain few substances to the exclusion of others formerly 

 in considerable repute. 



Paris green and other arsenites, kerosene emulsion, hydrocyanic- 

 acid gas, carbon bisulphid, and the lime, sulphur, and salt w^ash com- 

 prise the more important insecticides used to-day. To the three 

 principal periods in the evolution of insecticides in the United States 

 must now be added, in the writer's opinion, that in which was dis- 

 covered the efficiency of the lime, sulphur, and salt wash in the East. 

 The demonstration of the value of this wash, made almost simul- 

 taneously by several workers, ranks among the most important of the 

 notable advances in economic entomology in recent times. The 

 extensive experiments made with this wash under varying w^eather 

 conditions in Illinois, Georgia, Ohio, Maryland, New York, Con- 

 necticut, and other States now permit no reasonable doubt as to its 

 efficiency in controlling the San Jose and other scales in orchards, 

 and it has already been largely adopted by commercial orchardists. 

 It is possible that further experiments may reduce the inconvenience 

 at present involved in its preparation, and may modif^y its disagree- 

 able character. Should this be accomplished, the two features which 

 now constitute a ground for objection to its use would be eliminated. 



The importance of purely agricultural methods in reducing insect 

 losses, especially to some of our staple crops, is becoming much more 

 generally realized than heretofore. A series of demonstrations of 

 this character during the past few years may be held to mark another 



