212 
INSECTS IN THEIR RELATION TO AGRICULTURE. 
Delivered before an Evening Class for Farmers, College of Agri- 
culture, Territory of Hawaii, February 25th and 28th, 1908. Illustrated 
by lantern slides. 
By D. L. Van Dine. 
Lecture I. 
Authoritative writers have made the statement that ten per 
cent, of all farm crops are destroyed by insect pests. As this 
amount represents the average loss, then the loss in some in- 
stances must far exceed this. Actual figures would 
be startling. The farm crops of the United States amount to 
hundreds of millions of dollars and ten per cent, of this im- 
mense sum is destroyed by plant-feeding insects. Is there any 
wonder that there has developed a science of economic en- 
tomology ? The importance of insects in their relation to agri- 
culture has given the study of injurious insects and the prob- 
lem of their suppression a permanent place in every well 
organized agricultural institution throughout the world. I 
appreciate the honor of first presenting the subject to you, the 
first students of the College of Agriculture of Hawaii. 
If this age in which we live stands out in the future history 
of the world for any one thing, it will be the universal appli- 
cation of the results of scientific research for the betterment 
of man's condition. The application of the science of entomol- 
ogy to agriculture has made it possible to extend the culti- 
vated area of the world's surface and increase many fold the 
returns from the soil. The development of economic entomol- 
ogy has been in direct proportion to the farmer's ability to 
understand, appreciate and apply the results of the work of 
the investigator. Profitable returns from agricultural opera- 
tions depend upon an understanding- of this subject. It will 
not be your privilege to go deeply into the study in a well out- 
lined course of an extended period. The most I can do in a 
brief consideration of a very long subject will be to attract 
your attention to one phase of modern agriculture, your knowl- 
edge of which will depend for the most part on your own 
powers of observation and your ability to obtain aid from books 
and official publications that will help you. 
Before we can deal with any particular insect-pest problem 
successfully, something must be known of the general sub- 
ject, [n number of species and individuals, the insects ex- 
ceed all other animals combined. Numerically, as well as 
•economically, they command our attention. It is to be hoped 
that your interest, aroused through necessity, will carry you 
further than the economic phase of the subject. If it does, 
