13 
Tt 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 
output of the crop attacked, does not represent a- corresponding loss 
in money to the growers, 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 should 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 ways 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 prominently injurious species their life histories have been 
worked out, their most vulnerable points of attack shown, an«l 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 wash 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 weather 
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 modify 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 
