28. Contagious Diseases of the Chinch-bug. 
corn-fields; bugs quite plentiful in all of these. Sporotrichum 
abundant. 
June 27. Cherryvale, Cowley county, Kansas. Six fields 
were found where chinch-bugs were present. Sporotrichum 
was present in fields; in two cases it was plentiful. 
Experiments with Barrier and Post-hole Traps.—We believe that 
the best combination barrier and trap yet proposed is the one 
first described in our fifth report, January, 1895. It consists 
of a ridge of earth, smooth, compact, and rounded, bearing 
along its top a line of coal-tar. The bugs are trapped in post- 
holes, dug to a depth of at least twenty inches, contiguous to 
the tar line and on the same side of it as are the bugs, and 
placed about fifty feet apart. This experiment, as has been 
stated before, is to be used when the bugs are moving from one 
field to another, as when they are about to enter the corn. At 
such times they are often massed together in incredible num- 
bers. And in the progression toward the corn, when they reach 
the repellent coal-tar they move along it in an endeavor to find 
an opening through it and crowd themselves into the post-holes. 
As the holes are made larger at the bottom than at the top, the 
bugs cannot extricate themselves, and there perish. 
The longitudinal mound or ridge should be made smooth and 
hard, so that the tar will not be absorbed into the ground and 
so that rains will have a smaller effect upon it. It is much 
better to lay a line of tar along a ridge than along a furrow or 
a level place, because the former will shed the water and the 
line is much less likely to be interrupted by the blowing upon 
it of clods, leaves, sticks, etc. 
As the bugs will take advantage of every break in the line, 
or of the drying of it, a careful watch upon it should be kept, 
and it should be renewed from time to time. 
The first step in the making of the ridge is to plow two 
closely parallel furrows, running the plow so that the earth 
from the furrows shall mound up between them. ‘The re- 
sulting ridge should then be shaped and smoothed. For this 
purpose Mr. F. E. Marcy, an assistant of the Station, has con- 
structed a simple drag with a concave running surface. See 
plates I, II, III. With such an implement the ridges can be 
much more quickly, easily and properly constructed than if the 
operator must depend upon his ordinary shovels, hoes, etc. 
