INJURIOUS INSECTS OF 1909 AND IQIO. Al 
passing through the hopperdozer and striking against a bumper at 
about its middle, and the adults of EF. mali being shaken off from 
the trees, and flying in all directions, and naturally a great many 
of them lighting on the sticky oil or tanglefeot, and thus being 
caught and destroyed. 
The experiments with the hopperdozer were carried out in the 
nursery of Mr. Wedge, at Albert Lea, on August 5th. The general 
idea and plan of the hopperdozer seemed to be good, but it was 
found to be too heavy for practical work cn a large scale. It was 
found that the hopperdozer was much larger than necessary. As 
the average height of the young trees which are most affected is 
less than four feet, we found that the bumper was too high, as it 
would not touch the trees. We then lowered the bumper as low as 
it would go—within six inches of the bottom of the hopperdozer— 
and raised the handles so it would allow the hopperdozer to swing 
within six inches of the ground. In this way we were able to use 
it for the experiments. We found that the bumper was too far 
forward, as it would strike a tree and cause it to bend forward and 
strike other trees ahead, thus disturbing the leaf-hoppers before the 
hopperdozer got to the trees on which they were, and shaking them 
off in large numbers. We found that, by the trees being disturbed 
so soon, fully nine-tenths of the hoppers escaped from the interior 
portion of the hopperdozer without touching it. Practically all 
those which were caught were caught on the very front edges of 
the hopperdozer. We found that the crude oil was not effective, 
as the hoppers did not seem to cling to it very well; but the tree 
tanglefoot caught practically all that came in contact with it. 
We found that the canvas curtains at the back of the machine, 
when they were covered with the crude oil, daubed the leaves of the 
nursery stock; and it is doubtful if these curtains are of any value, 
as the hoppers did not seem to fly backward at all. 
The following counts were made on the apple stock in the 
rows after the hopperdozer had been run over the trees. Ten trees 
were taken for each count, and in all but the first two cases every 
third tree was taken. 
HES eNO BELO LC Githers sore! -) aie wie eco chee = 10 trees, 7 young, 3 adults found on trees 
2d row, next to treated row........ 10 trees, 59 young, 60 adults found on trees 
ey MeL Olursrt bl GcuUiC Un val. ore of ots (ess Yate ataueuceyie 10 trees, 35 young, 12 adults found on trees 
4th row, next to treated row...... 10 trees, 42 young, 14 adults found on trees 
5th row, nine rows away from treat- 
SO OWS acess eiste aie ore ote sie see 10 trees, 86 young, 42 adults found on trees 
