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



that it might be ascertained if other species would also be commonly 

 reared. 



Although the ladybird Hippodamia amoigua Lee. was observed 

 during the entire time occupied by the observations on the rose aphis, 

 it occurred in small numbers, and on only one or two occasions did it 

 seem to be feeding on Macrosiphum rosx. 



DISEASE. 



On March 14, 1910, after a night of rain, one winged and two 

 wingless aphides were found enlarged to fully five times their regular 

 size, as if bloated. This was probably due to a fungous disease. 



EXPERIMENTS WITH REMEDIES. 



The abundance of the rose aphis is so marked in many years that 

 frequently almost daily complaints of damage are made in the Dis- 

 trict of Columbia and vicinity. Wherever it has been convenient or 

 desirable to eradicate this species on small acreages of plants, water, 

 applied with a garden hose or syringe, has been the remedy employed, 

 not alone by the writer but by many persons resident in Washington. 

 Indeed this treatment, which consists in directing a forcible stream 

 of water against the affected portions of the plants has been one of 

 the standard remedies advised. Experiments have been made by 

 Dr. F. H. Chittenden, by Mr. C. H. Popenoe, and by Mr. A. B.Duckett, 

 all in the District of Columbia and vicinity. In other regions, Mr. W. B. 

 Parker has undertaken experiments with nicotine sulphate, and the 

 writer has conducted quite a series of experiments with the same 

 compound. Among other compounds used by Messrs. Chittenden and 

 Popenoe for this species are aphis punk and other nicotine papers, 

 always with gratifying success. While treating other forms of insects 

 on roses, such as "slugs" and thrips, the aphides were always the 

 first to perish. 



EXPERIMENTS IN THE DISTRICT OF COLUMBIA AND VICINITY. • 



On March 28, 1913, at Washington, D. C, four rosebushes in the 

 greenhouse, well infested by the rose aphis, were sprayed with "black- 

 leaf 40," a preparation guaranteed to contain 40 per cent of nicotine 

 sulphate, in combination with whale-oil soap in the following formula: 



Nicotine sulphate ounce . . J 



Whale-oil soap pound. . £ 



Water : gallons. . 2\ 



Although the solution slightly injured the terminal buds and the 

 tender shoots, the results were all that could be expected, 100 per 

 cent of the aphides being killed. It is believed that the solution 

 could have been reduced 25 per cent in strength with equally good 

 results. 



' By A. B. Duckett. 



