REMEDIAL AND PREVENTIVE MEASURES 



73 



been employed to good advantage since. The side of the tur- 

 row or trench next the field to be protected should incline 

 obliquely so that the upper part will be nearer the side toward 

 the worms than the lower part, thus rendering its ascent more 

 difficult. In cases where holes are not dug in the bottom of 

 the trench to trap the worms, they may be killed by dragging 

 boards or small logs along, or by strewing the trench with 

 straw from time to time and then burning it. 



JPencing Out. — Some years ago Dr. C. V. Riley wrote : 

 "From experiments which I have made, I am satisfied that 

 where fence lumber can be easily obtained it may be used to 

 advantage as a substitute for the ditch or trench by being 

 secured on edge and then smeared with kerosene or coal tar (the 

 latter being more particularly useful) along the upper edge. 

 By means of laths and a few nails the boards may be so secured 



Fig. 9. Standard Paris Green Duster. (Original). 



that they will slightly slope away from the field to be protected. 

 Such a barrier will prove effectual where the worms are not 

 too persistent or numerous. When they are excessively- 

 abundant they will need to be watched and occasionally dosed 

 with kerosene to prevent their piling up even with the top of 

 the board and thus bridging the barrier. The lumber is not 

 injured for other purposes subsequently." 



Poisoning. — One of the simplest ways of preventing injury 

 by the army worm, where it can be done without danger to 

 livestock, is that of dusting or spraying with poison a strip ot 

 grass or grain in advance of invaders. The simplest way of 

 doing this would be to apply Paris green when the dew is on 

 in the morning by means of one of the insecticide bellows now 

 upon the market, designed more especially for use against the 

 potato beetle. We have used two patterns of these this season. 



