14 BULLETIN 90, U. S. DEPARTMENT OF AGRICULTURE. 



containing 40 per cent of nicotine at the rate of 1 part of the solution 

 to from 1,000 to 2,000 parts of water, with whale-oil soap at the rate 

 of 1 pound to 50 gallons of spray mixture. When only a few rose 

 bushes require treatment the spray may be prepared in small amounts 

 as follows: To 1 teaspoonful of 40 per cent nicotine solution add 1 

 to 2 gallons of water and one-half ounce of whale-oil soap. The soap 

 should be shaved fine and dissolved in hot water. 



There are on the market numbers of solutions containing less nico- 

 tine than the foregoing which may be used with good results with 

 the addition of whale-oil soap, as advised, at the strength recom- 

 mended by the manufacturers. If these are not obtainable, very 

 good results may be accomplished by dissolving 1 pound of whale- 

 oil soap or 2 pounds of common laundry soap in from 4 to 6 gallons 

 of water. Wherever possible, however, the nicotine solutions should 

 be used, as better results will be obtained. 



This species, like practically all of the green aphides, can also be 

 controlled by repeated applications of a forcible stream of cold water. 

 Since the roses in California and some other localities are much sub- 

 ject to mildew, repeated use of this method has the disadvantage of 

 increasing injury by this disease. In the case of the appearance of 

 mildew, however, either through syringing with water or through 

 the application of nicotine sulphate, this disease may be readily con- 

 trolled by adding to the nicotine sulphate solution copper sulphate 

 or blue vitriol at the rate of 1 pound to 50 gallons of water (approxi- 

 mately 1 ounce to 3 gallons). A solution of copper sulphate used 

 at this strength and sprayed on the plants after the application of 

 the water treatment is effective in controlling the mildew. Another 

 common practice of florists for the prevention of mildew is to dust 

 the plants immediately after sprinkling or watering with common 

 flowers of sulphur. 



In order successfully to fight this insect these sprays should be 

 applied with a compressed-air sprayer (PI. Ill) or bucket pump 

 capable of creating a fine penetrating spray. These pumps can 

 usually be purchased at the seed stores at from $3.50 up to $15. The 

 nicotine solutions are also carried by most seed stores. Where a 

 pump is not to be obtained much can be accomplished by dipping 

 the infested twigs into a pail of the solution of nicotine. 



From the experiments of the writer it is evident that this insect 

 can be destroyed easily by the use of nicotine solutions of considera- 

 bly less strength than have heretofore been used, but the treatment 

 must 1)0 repeated at intervals to kill the aphides missed by former 

 applications. With the different stylos of pumps now on the market 

 at low prices no one who cares for roses has the slightest excuse for 

 allowing them to be injured by this insect. 



