58 JOURNAL OF ECONOMIC ENTOMOLOGY [Vol. 2 



shields, for instance, every day for a week at the time they first ap- 

 pear. We have made use of sticky shields with good results. A light 

 frame was made three by four feet, with handles, covered with heavy 

 cloth, and smeared with tree tanglefoot. A thinner grade of tangle- 

 foot than this might have been used advantageously. Two men were 

 employed in this work, one man holding the frame and walking down 

 one side of the row of trees, while the second jarred the trees from 

 the other side. Two men in ten minutes covered two hundred and 

 ninety feet in a row, and an actual count of hoppers caught in the 

 ten minutes was 3,221. About 95 per cent of these were adults. 



Spraying the trees with any compound does not seem advisable, on 

 account of the difficulty of hitting the insects in the curled leaves, but 

 we found that a spray of one pound of fish-oil soap in ten gallons of 

 water killed both adults and young, when not too well concealed in 

 the leaves. 



For use on experimental plots, we constructed a hopper dozer, with 

 a metal pan to hold petroleum. By once employing this on alfalfa 

 plants we believe we killed nearly 50 per cent of the insects present 

 at that time, and it would seem that it could be used to advantage on 

 a commercial scale with any low-growing plants set in rows. 



President Forbes : Discussion is next. 



]Mr. R. L. Webster : Mr. President, I would like to make a few 

 remarks on the number of broods, comparing INIinnesota conditions 

 with Iowa conditions. I see Professor Washburn has succeeded in 

 getting only three broods. I have pretty conclusive evidence that in 

 Iowa we have five broods. That is, at the rate of one brood for every 

 month. About once a month, I think it is the last few days of one 

 mouth and the first few days of the next, they appear on the young 

 tender shoots on apple stock, as shown by the curling leaves, which 

 is coincident with the appearance of the newly hatched insects. The 

 leaves first come out in southern Iowa about the latter part of April, 

 and with them appears the first brood of young leaf hoppers. The 

 insect winters in the egg stage, as it does in INIinnesota. Counting 

 one brood a month, by the first of September we have five broods, and 

 the winter eggs are deposited in the bark about the first week in 

 October. I found them at Charles City, about the sixth of October, 

 thus making five broods. 



Mr. Washburn : It is very strange that we found clusters on the 

 23d of September. I don't know why we should. Of course, being 

 further north, they would begin laying their eggs sooner. This was 

 at St. Anthonv Park. 



