PESTS OF THE ROSE 161 



ruined. Moreover, a strong corrosive wash is not necessary to 

 kill aphides. All that we have to do is to block up the breathing 

 pores, and so asphyxiate them. This may be done with simple 

 soft soap and water. For the spraying of roses you must get the 

 best soap, and not use more than one pound to twenty-five gallons 

 of water. To this may be added two and a half pounds of quassia 

 chips. The effect of the latter is undoubtedly most beneficial, 

 for it acts as a stimulant and cleanser to the leaves, and by many 

 growers is said to have a direct effect on the aphides. The soft 

 soap has some corrosive power, for it contains caustic soda (about 

 4 per cent.). This soft soap and quassia wash is made as follows : 

 Dissolve the soap in boiling soft water ; boil the quassia chips, 

 and let them simmer for about twelve hours, adding water enough 

 to keep them covered. Every now and then strain off the liquid 

 extract and pour into the dissolved soft soap, and well stir, and 

 lastly, add the full quantity of water of dilution. This is all that 

 is required to kill aphis ... To clear the roses, we must spray 

 twice in succession on two consecutive days. Nicotine is an 

 excellent insecticide, and may be safely used with soft soap." 



Mildew is perhaps the most difficult of the enemies of the rose 

 to overcome. The fungus first appears as a white mould on the 

 foliage of the trees, and unless it be promptly checked it will 

 spread, until the whole collection has become affected. The best 

 way to check the disease in its early stages is to dust sulphur 

 powder lightly over the affected leaves. The sulphur should be 

 put in a fine muslin bag and be shaken over the leaves on the first 

 calm evening after the disease is detected, this operation to be 

 repeated at intervals until the mildew has been eradicated. In 

 cases where the disease has not become rampant spraying may 

 be recommended as a preventive. The preparation recommended 

 in the Rose Society's booklet is a solution of potassium sulphide, 

 popularly known as " liver of sulphur." One ounce should be 

 dissolved in five gallons of rain water, and if a tablespoonful of 

 liquid glue is added the fungicide will adhere much longer to the 

 foliage. 



The frog -hopper, or cuckoo -spit insect, generally makes its 



