15 



As a result of a continuation of this rotation the pest lias been practi- 

 cally exterminated, thereby, according to Mr. Fowler's estimate, saving 

 him $10,000 per annum. 



Professor Osborn has shown that grass insects destroy much produce. 

 He estimates that the small leal-hoppers (Jassuhr) destroy as much food 

 from two acres of pasture as would feed one head of stock. From re- 

 cent experiments he has found that it is possible by the use of hopper- 

 dozers to reduce the numbers of these insects so materially that, upon 

 two plots chosen for their similarity of the conditions of the growth, 

 the amount of hay produced upon a plot which was once treated with 

 the hopperdozer was 34: per cent greater than upon the corresponding- 

 untreated plot. 



I have said that the study of economic entomology is many sided and 

 requires many workers. It is equally true that all who would keep up 

 with the rapid development which is going on all the time must work 

 day and night, early and late. The various habits of so many diflerent 

 objects of study, many of them nocturnal, require constant attention. 



In conclusion, I would urge on every one the great importance of keep- 

 ing the most careful notes of everything which affects their work, not 

 only of what is seen in one's own investigations, but of whatever is 

 found in the literature of the diflerent subjects studied. There is per- 

 haps no detail of our work which so well repays the slight extra trouble 

 which it involves as making all notes carefully, completely, and neatly, 

 and then putting them away system aticall}^ so that they can be found 

 when required suddenly on some future occasion. Our " private notes," 

 as we call them, should, I think, be made with the greatest possible 

 care, not oulj- for our own sakes, but to insure that they may be of use 

 to others after we are gone. Who has not felt the disappointment on 

 looking through the collection of some great worker suddenly called 

 away from this life, of finding rare and interesting specimens, without a 

 single note of locality, date, or other information, and how compara- 

 tively useless such specimens, and even the labor by which they were 

 bred or procured, are thus rendered. We all know this, and yet how, 

 too often, do we put aside material without labels, thinking that we 

 know and shall remember all about them. After many years of much 

 wasted labor I have come to the conclusion that a few specimens well 

 preserved, properly mounted, and with full notes, are far more valuable 

 than a large number of specimens without these characters. When a 

 collector once gets the habit of accumulating a large number of sjieci- 

 mens of everything he sees, he very soon gets careless about putting 

 them awa}' while they are in good condition, and has not time to make 

 the proper notes. 



Not only should notes be taken of what we ourselves have seen, but 

 much time will be saved if an index book be kept of all literature which 

 passes through our har.ds. Even in this we must i)rotect our ourselves. 

 The time of an enthusiastic entomologist is necessarily short, and he has 



