ENEMIES OF THE ROSE 93 



when the leaves are expanding, be sprayed with a solu- 

 tion of potassium sulphide, and where rust marks exist 

 on the wood they should be treated with equal parts of 

 methylated spirit and water, rubbed well in with a bit 

 of sponge. 



Black spot, the appearance of which is described by 

 its name, is the third of the commoner diseases of the 

 Rose. It is treated in the same way as Rose rust, by 

 burning all infected leaves and spraying with potassium 

 sulphide or some other good fungicide. 



One of the chief of the insect enemies of the Rose is 

 the green-fly or aphis. These insects, if they are treated 

 and dealt with drastically on their first appearance the 

 finger and thumb being the instruments employed may 

 be easily kept in bounds, but if they are once allowed to 

 get a start, more serious measures are called for. Sharp 

 syringing with plain water, or water mixed with a good 

 insecticide, always remembering not to use it too strong, 

 will be found effective. One of the best washes for 

 green-fly is the following : One pound of quassia, half a 

 pound of soft soap, and ten gallons of water ; this to be 

 sharply sprayed or syringed on to the affected shoots. 

 The spraying should be done on two successive days so 

 that both the parents and the young may be killed. 



The aphis has many natural enemies, and the wise 

 Rose grower will not discourage these from frequenting 

 his garden. They include the lady-bird, which both in 

 the larva and the perfect stages devours the aphides 

 ravenously ; the lace-wing fly, who lays her eggs on 

 curious long stalks, and is another helper, as her larvae 

 eat an incredible quantity of the aphides, sucking their 

 juices and picking them off the leaves by means of special 

 sickle-shaped jaws ; and various other flies which are of 

 great assistance in keeping down the green-fly. These 

 two, however, are the chief among them. 



The best way of ridding the plants of grubs and 



