AND OTHER INJURIOUS INSECTS OF I907 AND I908. 



25 



rather stiff in consistency, and a thinner grade could have been used 

 and covered more surface. One man held the frame by the handles, 

 walking down one side of the row of trees, while the other jarred 

 the trees from the other side. A gentle breeze was blowing at nearly 

 right angles with the rows, and the shield was used on the side facing 

 the wind. The hoppers left the trees in swarms when jarred, and 

 flew with the wind and downward, the greater part of them being 

 caught by the tanglefoot on the stickv shield. On account of the fact 



Fig. 9. Sticky shield in use in nursery. 



that the hoppers flew downward, more were caught on the lower side 

 of the frame than on the other. Two men, in working for ten min- 

 utes, covered two hundred and ninety feet in a row of five-year-old 

 apple stock, and an actual count of the number of leaf hoppers on the 

 frame caught in ten minutes' work was 3,221, on a surface 3 by 4 feet. 

 About 95% of these were adults. 



This experiment was made at Owatonna the 19th day of July, 

 when most of the hoppers on the trees were adults. Doubtless such 

 a time would be the best to make use of the sticky shields, but a 



