22 STATE BOARD OF AGRICULTURE. 



lime slowly to the copper solution, stirring constantly, and strain 

 through a sieve or coarse gunny-sack ; finally, add 20 gallons of 

 water and the mixture is ready for use. This gives the standard, full- 

 strength mixture, which can be reduced by the addition of water to 

 any desired point. 



Paris green, green arsenoid or white arsenic may be added to this 

 bordeaux mixture where a combined insecticide and fungicide is 

 desired, and for insecticide purposes the fungicide may be counted as 

 so much water in determining the amount of poison to be added. 

 The excess of lime in the bordeaux mixture as prepared above is 

 sufficient to neutralize the free arsenious acid in the insecticides. It 

 is said that the arsenate of lead may also be used with the bordeaux 

 mixture, but with this I have no personal experience and do not 

 advise it. The green arsenoid is the best material for the purpose 

 from its composition. 



No other fungicide preparation adapts itself to a safe mixture with 

 the arsenical insecticides and no other combinations are recommended. 



Tobacco and hellebore have some value as stomach poisons, yet 

 their best effect is obtained by bringing them into actual contact 

 with the insects. 



Hellebore has a very limited range and is mainly useful against the 

 larvae of saw-flies, like the currant worm, and against such it is 

 almost a specific. It may be applied dry, as a powder or in the form 

 of a decoction, using one or two ounces in one gallon of water, ac- 

 cording to the age of the insects operated against. 



Tobacco has a much wider range of usefulness and is really a very 

 important insecticide, though somewhat expensive. It may be applied 

 dry, as a very fine powder, or in the form of a decoction. The 

 tobacco powder is often a useful repellant applied at the base of trees 

 or plants to avoid injury from root maggots or borers, and dug into 

 the soil about a tree infested with root lice it is doubly useful in 

 destroying the insects and acting as a fertilizer. 



Tobacco stems about the base of trees are absolutely useless and a 

 detriment rather than otherwise. The killing agent is nicotine, and 

 the tobacco must be in such state that a good rain will dissolve this 

 all out and bring it into contact with underground pests— otherwise 

 no advantage will be derived. 



If used dry against plant lice it must be very finely ground to pene- 

 trate into the spiracles ; otherwise it is no more than so much coarse 

 sawdust. 



Its range as a decoction is much greater and extends to all plant 

 lice, to thrips, mealy bugs, j^oung leaf hoppers and some other soft- 



