od of attack of the insects with sucking mouth parts is 

 quite as characteristic and easily recognized. 



POISONING. 



If we determine that the insect in which we are inter- 

 ested, is of the biting type, devouring foliage, perhaps, then 

 we know that it actually takes in particles of the plant as 

 iood, and we can infer that if poison is placed on this fo- 

 liage it will become a part of the insect's diet and cause its 

 -death. On this determination will depend our use of such 

 poisons as Paris green, arsenate of lead and similar toxic 

 -agents. These are known as internal or stomach poisons, 

 -are effective only when taken into the digestive tract, and 

 do not trouble the generality of insects when in contact 

 with them externally. 



Spraying With Paris Green. Paris green is an insol- 

 uble compound of arsenic and copper, and has received 

 Tiiore attention and use in farm practice than has any other 

 arsenical. If properly prepared it should carry but an 

 extremely small percentage of free arsenic, and under these 

 conditions it is generally not injurious to foliage, while be- 

 ing a very effective insecticide. It may be used as a spray 

 in water or may be dusted on the plants or trees to be pro- 

 tected. When used as a spray the mixture should be made 

 as follows : 



Paris green 1 pound 



Stone lime 4 pounds 



Water 200 gallons 



Mix the Paris green to a paste in a small quantity of wa- 

 ter and then put in the spray tank with nearly the total 

 ^amount of water to be used. Slack the lime in enough wa- 

 ter to break it down completely, being careful, however, not 

 t:o use enough water to "drown" it. Strain tne milk of lime 

 thus obtained through a sieve into the spray tank. Keep 

 the whole mixture thoroughly and constantly stirred while 

 spraying. In using this material as a spray, care must be 

 exercised not to put too much upon the tree to be protect- 

 ed. While enough should be sprayed on to cover the leaves 



