CHINCH BUG WEST OF MISSISSIPPI RIVER. 37 



twofold value; first, it will kill large numbers of bugs directly; and, 

 second, the bugs not killed by the fire will be left exposed to the 

 winter freezes, which of themselves will in ordinary seasons kill 

 many of them. On several occasions during fall and spring bugs 

 were removed from the stubs of burned grass and the percentage of 

 dead and live bugs obtained. On an average about 75 per cent were 

 killed in the fall and about 63 per cent in the spring. In the spring 

 about 20 per cent of the bugs, winch hibernated in the clumps of 

 grasses, were dead from exposure and other causes. From natural 

 causes and burning in spring, there were about 83 per cent of the bugs 

 dead. These percentages were obtained by actually counting the 

 insects and are not from estimates. The fire can not reach all the 

 bugs, even with the most careful burning, because of protection 

 afforded by green or wet stems in early fall and late spring; therefore 

 it is essential that the grass be burned during late fall or early winter. 

 While this remedy is recommended above all others, its effectiveness 

 is entirely dependent upon the farmers and their cooperation, and 

 it is an easy matter for neighborhoods to combine in an effort to fight 

 the pest in this manner. 



DUST BARRIERS. 



If the bugs are not killed out during hibernation, the main de- 

 pendence of the corn grower must be in the destruction of the bugs 

 as they migrate from the ripening small grain to enter the corn- 

 fields. As soon as the ripening grain compels the bugs to desert it 

 and they start for the corn, a narrow strip of ground between the corn 

 and wheat should be deeply plowed and thoroughly pulverized, 

 making a dust bed. Then a short block or a triangular box should be 

 made in form of a sled with the bottom fitted with a seat for a driver. 

 This should be dragged back and forth in this dust bed until a deep 

 groove or furrow has been made. If this furrow has been .well pre- 

 pared, and the weather continues dry, it will prove an impassable 

 barrier to the progress of the bugs. In order that this kind of barrier 

 may be successful, the block must be kept in Constant use, from early 

 until late and sometimes well into the night. Often, during the migra- 

 tion, the bugs travel all night. Slight showers render dust furrows 

 useless and if a shower is pending, and under such weather conditions, 

 it is best to employ the coal-tar barrier. Owing to the fact that dry 

 weather often prevails on the plains during this season the furrow 

 method under these conditions is especially recommended. 



COAL-TAR BARRIERS. 



The coal-tar barrier can be operated successfully in the Middle- 

 Western States to prevent the bugs from migrating to young corn. 

 The success of this measure depends on the farmer and his careful 



