30 



Nozzles. — Much of the success in spraying depends upon the kind of 

 nozzle that is used. Fig. 10 illustrates the Vermorel nozzle, and Fig. 11, 



the Bordeaux nozzle, both of which 

 throw the liquid out in a very fine 

 spray. In using these nozzles, all 

 coarse particles of lime or other 

 substances must be strained out of 

 the liquid. 



Insecticides. — Insecticides or in- 

 sect destroyers may be divided into 

 two groups, i.e., (1), those that kill 

 chewing insects, like the potato 

 beetle and its larvae, the larva? of 

 the canker worm, etc., and (2), those 

 that kill sucking insects, like the 

 aphides (plant lice), the pear psy 11a, 

 the black squash bug, etc. 



In the first group are Paris 

 green, London purple, arsenate of 

 lead and hellebore. 



Paris Green. — This is the most 

 generally known and one of the 

 most effective insecticides. It is used 

 in a solution of 2 lbs. to 150 gallons 

 of water, or in a dry powdered form 

 with bellows or guns, and in this 

 form must be applied when the fol- 

 iage is more or less wet with dew 

 or rain. If used too abundantly and 

 "the weather following is very wet, 

 serious injury often follows. Num- 

 erous substitutes for this insecti- 

 cide have been offered in the market under various names but none of 

 them have proved of sufficient value to be recommended. 



Fig. 9. 



- London Purple. — Owing to the variable nature of this substance it has 

 not come into such general use as has Paris green. Upon crops that are 



