22 



at small expense afford the best possible proof of th<nr practical utility. 

 If a farmer is situated near town, where refuse tin cans are (Unni)ed 

 in any locality where they can be got out of the way, he can select 

 the larger of these, set them in the post holes and ])artly fill them 

 wdth kerosene and water. The water, being heavier Ihan the kero- 

 sene, will sink to the bottom, leaving a stratum of kerosene on the 

 surface. The chinch bugs falling into this will be forced down by the 

 weight of those coming after, and thus all will be passed tlirough the 

 kerosene into the water below. This will obviate the necessity of fre- 

 quently emptying the cans or treating their contents. It may also 

 be stated that where the post holes are quite deep and enlarged at 

 the bottom the bugs falling into them will perish without further 

 attention. 



OTHER BARRIER METHODS. 



The late Professor Snow, working in Kansas, followed a somew hat 

 different method, and one that, under certain conditions, might be 

 found superior to that used by Professor Forbes, or the furrow and 

 kerosene method applied by the writer in Ohio. This modification 

 consists in -throwing up a double furrow, known among farmers as 

 "back furrowing," and thus forming a ridge, the top of which is 

 smoothed and packed with a drag having a concave bottom of the 

 form of the ridge to be made. If the bottom of this drag is covered 

 with zinc, it will be found to keep bright and polished, and by this 

 me.ans make a smoother ridge. Along the top of this ridge is run a 

 train of coal tar as it came from the gas works, or crude petroleum as 

 taken from the oil wells. The former is more easily obtained, except 

 in certain localities, and will probably be found the more practical, 

 as it stands on the surface better and is not so readily washed away 

 by rains. Both of these substances are, however, offensive to the 

 bugs, and they will seldom attempt to cross them or even come close 

 ent)ugh to touch them, but on approaching will turn and run along 

 the ridge in the evident hope of finding a. gaj) tlirough which they can 

 pass. Post holes were dug on the outside of the line, but close up to 

 it, so that the bugs in passing along beside the tar line would crowd 

 each, other into them. Professor Snow suggested that it will be better 

 to construct this barrier several weeks prior to the time when it will 

 be needed, as then the tar Hue has but to be run along the ridge, and 

 the post holes dug, when the whole system is complete, and the 

 chinch bugs can be thus shut out from the first." 



With these barriers of either ridge or furrow and the use of coal 

 tar or crude petroleum, supplemented by kerosene emulsion, a very 

 large percentage of the injur}^ from chincli bugs may be obviated, 



"Fifth Annual Report of the Director of the Experimental Station of the University 

 of Kansas, for the year 1895 (1896), pp. 45-47. 

 ICir. 113] 



