108 JOURNAL OF ECONOMIC ENTOMOLOGY [Vol. 5 



tains of West Virginia, secured on railroad trips, which all tends to 

 show that there is a principle here which can be utilized and that it 

 has a broad practical application, not only in the control of insects, 

 the study of life histories of insects, but for the planning of farm oper- 

 ations. 



The fact of it is, farmers have recognized and utilized the principle. 

 I remember when I was a boy that the farmers in the community 

 where I was reared planted their corn when the dogwood was in bloom 

 and the new leaves on the white oak were the size of squirrel feet. 

 They had determined, from long experience, that, when the corn was 

 planted at that time, they had the best results. The dogwood and 

 the white oak served as the index. Therefore, we have, all through 

 the country, every spring, similar indexes which can be recognized 

 and utilized as guides to the proper time to do things. During the 

 present year we conducted extensive demonstrations in the control 

 of barkbeetles over quite a large area in northeastern Oregon. The 

 area is practically in the same latitude, but there is quite a difference 

 in altitude. Now, our normal period for the ending of control opera- 

 tions is July 1st, because after that date, under average conditions, 

 the beetles begin to emerge from the trees. So we stopped operations 

 on July 1st, but I kept one of the Agents there to make continuous 

 observations until in August. He found that, while July 1st was the 

 proper date to cease operations at about 4,000 feet because at that 

 date the beetles were emerging and attacking other trees, at 3,000 

 feet higher up in the mountains it was just thirty days later when 

 they were eiifierging and attacking the trees. Therefore, control 

 operations could have been continued thirty days longer if we had 

 acted on that principle. Farther south here, of course, we would 

 have had to discontinue the work much earlier. This is simply one 

 example of the practical application of the principle. 



President F. L. Washburn: Anything further on this very inter- 

 esting and practical subject? 



T. J. Headlee: Mr. Chairman, I realize that in some branches of 

 our science there is too much of a tendency to theorize on a small 

 amount of data, and that is vicious, but, at the same ti_me, in our 

 economic entomological work, I have come to feel that there is not 

 enough theorizing, — that we work, perhaps, too long, on one subject 

 before we say anything about it. The result of that method is this — 

 that the younger men who are ready and eager to take up these impor- 

 tant subjects are not stimulated to do so. It seems to me, if the 

 older men in these lines of work would, from time to time, set forth 

 tentatively results that they have obtained, they would stimulate a 

 vast amount of work along their lines and that, in the aggregate, we 



