LEAF-HOPPERS. 25 
each holding a string fastened at the end and one fastened at 
the center, four strings in all. The advantage in having two 
men is that when alarmed by approaching foot-steps on either 
side, they will move centerward and be caught by the dozer, 
whereas when one man draws it and walks in front of the center 
they fly outward from his path on both sides and thus tend to 
escape. 
“In moving fifty-five feet with the dozer the number of leaf- 
hoppers taken was estimated by counting the insects on three 
sections of the dozer, each six inches long and extending the 
entire width of the dozer. The counts were 183, 319, and 226, 
respectively, which averages 243 for each section, or 4,131 on 
the whole pan. At this rate about 376,000 insects would be 
caught per acre. 
“Another test was made at the same time, dragging the 
dozer over 66 feet of lawn. ‘This time five sections of six inches 
each were counted off and averaged instead of three, which re- 
sulted in giving 2,805 insects on the dozer, or 213,089 would be 
taken on an acre. 
“Their wings at this time were so developed that many would 
fly entirely over the pan. At this stage the dozer should be of 
greater dimensions than ours, or used at hours of the day when 
hoppers are less active. The difference in numbers on the ground 
tun over with the dozer and that not cleared was not very no- 
ticeable and there can be no doubt that over one million leaf- 
hoppers can, and often do, live onan acre of ground. 
“The dozer will be found most effective while the insects 
are still immature and are unable to fly readily. 
“Other insects captured at the same time, and worth noting, 
were several of the Elateride or click beetles, the parent forms 
of the destructive wire-worms, some tineids, sod web-worm 
moths, and numerous Capside. 
“July 2nd the hay upon plats I and II was cut and the 
product of the two equal triangles carefully surveyed with a 
surveyors chain, and each containing 39-100 of an acre, was 
weighed and compared. The hay from the triangle on plat I 
weighed 338 pounds, or yielded at the rate of 876 pounds per 
acre. The hay from the triangle on plat II weighed 252 pounds, 
or yielded at the rate of 646 pounds per acre. The difference in 
