THE MONTHLY BULLETIN. 297 



SPRAYS AND POISONS. 



Sprayiiiii' for insect pests has become a very important factor in the 

 growing of all crops and especially in horticultural work. As such it 

 is now a regular and well established business, which has received a 

 tremendous amount of investigation work, with the results that there 

 is on the market a spray for every individual ailment a tree or plant 

 is heir to. This is true of both the home-made and commercial products 

 and it has become an exceedingly diiKcult task for the orchardist or 

 farmer to select a spray which is to give the best results for the financial 

 outla.y. 



It is beyond the limits of any ordinary work to give a complete list 

 of the formula^ and uses of all these preparations, and should this be 

 done the results would prove unsatisfactory. It is therefore the aim of 

 the writer to include only those preparation.s which are known to give 

 definite and reliable results. 



In general insecticidal sprays and powders are listed in three main 

 classes, viz: poison sprays, contact sprays and repellents. The poison 

 sprays are used in controlling biting and chewing insects which are 

 capable of taking the poison internally ; while the contact sprays are for 

 piercing and sucking insects which cannot be controlled by poison 

 sprays. The repellents do not kill, but applied to the plants or soils, 

 serve to drive the pests away and thus prevent attacks. 



POISON INSECTICIDES FOR CHEWING INSECTS. 



Poisoned sprays are usually made of arsenical compounds and are 

 therefore known as arsenical sprays or insecticides. Formerly Paris 

 green and London purple were used but of late years it has been found 

 that lead arsenate and zinc arsenite are as efficient, cheaper and do less 

 damage to the fruit and foliage. 



These sprays are used in combatting leaf eating insects, such as 

 grasshoppers, army and cut worms, tent caterpillars, red-humped 

 caterpillars, tomato and tobacco worms, cabbage worms, pear slugs, 

 beetles, etc. 



LEAD ARSENATE. 



No. 1. ('omniei-cially prepared. 



Lead arsenate (paste) G to S pounds 



Water 100 gallons 



No. 2. Arsenate of lead (powder) 2 to 8 pounds 



Water 100 gallons 



Preparation. — Simply dissolve the paste or powder in the required 

 amount of water or in a small amount and add the remainder for use. 



No. 3. Home-made preparations. 



Acetate of lead _i._l__^_ ' 44 ounces 



Arsenate of soda ^__^ 10 ounces 



Water lOO saHons 



