Sixth Annual Report. 39 
EXPLANATION OF PLATES. By 
PLATE I. Figure 1 shows the Marcy ridge-forming implement. To form the 
_ ridge, a double furrow is thrown up with the plow. The implement, which j 
has a concave bottom, is then drawn over the ridge, compacting and smooth- aha 
ing it at the same time. The clod cutters shown in front were found to be 
superfluous, their purposes being better fulfilled by stone piled on the 
implement to give it more facility for pressing the clods and for scouring. 
The handles were found necessary for holding the implement directly over 
the ridge. 
Figure 2 shows the implement at work. The round can attached to the 
_ rear was for the purpose of distributing salt and kerosene as the ridge was 
_ formed, but it was found more feasible to do this as a separate operation after 
the ridge was formed. The salt and kerosene were not found to be sufficient 
barriers under the meteorological conditions existing last summer. A line of 
coal-tar on top of the ridge was successful under all conditions. 
PLATE II. Figure 1 shows a field of corn which had been destroyed by chinch- « 
bugs as far in as the ridge shown, a little to the right of the center. After \ 
the ridge was formed and post-holes dug for traps and a stream of coal-tar run 
along the top of the ridge, the bugs got no further into the corn and did no 
more damage. 
Figure 2 shows a corn-field that was protected by the ridge and post-holes 
before the bugs had entered the corn from the wheat. The bugs were caught 
in great numbers in the post-holes and perished there. Before the picture ; . 
was taken the bugs were scooped from the holes and piled along the left-hand 
margin of the ridge, as shown in the picture. The corn suffered no damage 
whatever, although unprotected fields ao far distant were in some instances 
_ destroyed. 
PLATE III. Figures 1 and 2 show ridge formed by the Marcy implement. 
Post-holes were dug beside the ridge, about 100 feet apart. These should 
never be omitted in forming the barrier. Ridges formed in this manner are 
smooth and compact, and are very little affected by rain. They sometimes - 
last throughout the summer without being seriously damaged. 
' PLATE IV. Figure 1 shows a reel of tarred burlap which was used for a 
__ chinch-bug barrier. Stakes were tacked to the burlap every three feet, by 
means of which the burlap was fastened along the ground in an upright 
position, as shown in figure 2. It was found that after a rain the burlap 
would be covered with mud which had been splattered against it, and thus 
- rendered it inefficient as a barrier against the bugs. In fact, no device was 
found for all soils and seasons to equal the ridge with coal-tar and post-holes. 
, PLATE V. A picture taken in the field, showing scattered over the ground 
i chinch-bugs killed by and covered with Hmpusa. In the picture the bugs 
appear as nearly round or oval white bodies, about one-eighth inch long. 
_ Empusa appeared as an epidemic only after the atmosphere had been made 
humid by a long rainy period; then the wholesale destruction of the bugs was 
very striking. Hmpusa had not been distributed by the the Station in this 
ig locality, and its appearance must have been due wholly to natural causes. 
