and, in fact, with a reasonable degree of watchfulness and ])romi)t 

 action, all injury from migrating hordes may be prevented. The use 

 of tarred boards set on edge or slightly reclining might, under some 

 circumstances, take the place of the ridge or furrow, but these cases 

 will be exceptional, and the use of kerosene emulsion will ]iri»ba])ly 

 be found equally practicable here, as also will the post holes for col- 

 lecting the chinch bugs. This method is merelj'' cited in order to call 

 attention to its possible use where the others are found impracticable. 



THE USE OF FURROWS WITHOUT PETROLEUM OR COAL TAR. 



The plowing of furro^xs has been in vogue since the first writings 

 of Le Baron and the second report of Fitch, and may be utilized in 

 other ways than those previously mentioned. A heavy log dragged 

 back and forth in this furrow will pulverize the soil in dry weather, 

 and Doctor Forbes has recorded the fact that where tliis furrow has 

 a temperature of 110° to 116° F. it is fatal to the young bugs that 

 fall into the furrow, even if they are not killed by the log. As 120° 

 is not uncommon in an exposed furrow on a hot summer day, it will 

 be observed that there may be cases where this method ^^ ill be found 

 very serviceable, and especially is this likely to prove true in a sandy 

 soil with a southern exposure. In sections of the country where irri- 

 gation is practiced, tliese furrows may be flooded and in this way ren- 

 dered still more effective without the expenditure of either time or 

 money to keep them in constant repair. Riley long ago laid consid- 

 erable stress on this measure, believing it of much value, especially 

 in the arid regions of the far West. The same writer advised the 

 flooding of infested fields, wherever it could be done, for a day or so 

 occasionally during the month of May. It is hardly probable, how- 

 ever, that this will often be found feasible except in rice fields, where 

 it is sometimes practiced. 



NECESSITY FOR PREVENTING CHINCH BUGS FROM BECOMING ESTABLISHED IN FIELDS 



OF WHEAT AND GRASS. 



In the foregoing it will be observed that prevention of migration 

 has been the chief end in view, either by destroying the chinch bugs in 

 their hd)ernating quarters, and thus ])reventing the spring migration 

 to the breeding places, or by various traps and obstructions to ])revent 

 them from migrating from such ])laces to others not already infested. 

 The great problem remaining to be solved is to prevent their Ijreeding 

 in wheat fields at all. As has been shown, it is absoluteh" impos- 

 sible, with our present inability to forecast the weather months in 

 advance, to be able to foretell whether or not an outbreak of chinch 

 bugs is likely to take place. There may be an abundance of bugs in 

 the fall — enough to cause an outbreak over a wide section of country — 

 and these may overwinter in sufficient numbers to cause some injury 



[Cir. 113] 



