1902.] INSECTS RELATION TO AGRICULTURE. 193 



work of the second-year men is transferred to the field, and 

 during' the coming spring we shall probably be engaged in 

 practical forest work on a large tract of about 20,000 acres in 

 southeastern New York. 



• This brief sketch will give you an idea of the kind of work 

 we do in New Haven, and especially of our point of view. It 

 is our aim not only to acquaint the students thoroughly with 

 the principles and methods of forestry, but to produce efifective 

 men who have already had enough practical experience to 

 undertake the work for which there is at present so great 

 a need. 



The President. Are there any questions which you 

 would like to ask the professor? If not we will proceed to 

 listen to an illustrated lecture by Prof. Britton on " Insects 

 and their Relation to Agriculture." 



INSECTS AND THEIR RELATION TO AGRICUL- 

 TURE. 



By Mr. W. E. Britton, 



State Entomologist. 



The popular idea of insects seems to be that, as a class, 

 they are injurious, though such is hardly the case. Howard* 

 has shown that of the many families of insects, 116 are in- 

 jurious, 113 beneficial, while 71 families contain forms both 

 injurious and beneficial or their habits have not been de- 

 termined. 



Insects are found all over the earth, even in the arctic re- 

 gions, but are most abundant in the tropics. In early times 

 their outbreaks were regarded as plagues sent by the Al- 

 mighty, and against which nothing except Divine interposi- 

 tion could avail. It was not then considered, as now, to be 

 a question of the struggle for existence among species, nor 

 that man had the right or power to wage war against those 

 animals that destroyed his crops. 



Insects are called injurious because they devour plants, 

 stored grains, foods, books, clothes, etc. ; because they annoy 



•Address of the retiring President of the Biological Society of Washington, Jan. 

 18, 1899, printed in Science, Feb. 17, 1899. 

 Agr. — 13 



