HOP APHIS. 125 



In some cases a little soda is found serviceable, mixed with 

 the solution of soft-soap. 



An addition of some amount of paraffin to soft-soap wash 

 has been shown to be of use by the experiments of Mr. Ward 

 at Stoke Edith in 1883 and 1884. The proportions used by 

 him for large quantities were 12 lbs. of soft-soap and half a 

 gallon of paraffin to 100 gallons of hot water, the mixture 

 stirred well together and used when cool ; the nearer boiling 

 that the water is used the better the paraffin mixes. (This 

 wash is found to be very effective in killing the Aphides 

 without injuring the plant or the burr, but it requires such 

 great care in mixing, and also in use, lest the mineral oil 

 shoukl separate from the soft-soap wash, and also lest from 

 state of weather or any other circumstance it should injure 

 the leafage or burr, that I do not venture to recommend it as 

 a hroadscale remedy. — E. A. 0.) For methods of per- 

 manently mixing soft-soap and mineral oil, see Index. 



It is found that circumstances of locality, whether from 

 soil or surroundings, exercise an influence in the amount of 

 attack, as " In some districts the Hop -plants are more liable 

 to be blighted than others, and in most districts there are 

 * lucky ' farms upon which the Aphis blight or mould rarely 

 affects the plants. A hedge or a stream frequently forms a 

 line of demarcation between Hop-land that is liable to blight 

 and that which ordinarily escapes blight." — (C. W.) 



Weather influences have great effect on the Hop. Under 

 favourable circumstances it grows rapidly, especially in warm 

 nights — as much as four inches of growth having been 

 recorded as taking place in one night on bines. East winds 

 in the spring are unfavourable to the plants, and favourable 

 to Green Fly. The sunshine and warmth in sheltered posi- 

 tions which often accompany these winds, alternate with 

 frosts at night that check the growth of the tender succulent 

 shoots, and thus a state of sap is produced peculiarly suitable 

 to the Aphides, which increase rapidly under these circum- 

 stances. 



Practically it has been known as far back as Tusser's time, 

 that— 



" The wind in the North, or else Northerly-East, 

 Is bad for the Hop as a fray at a feast," 



and scientifically the recent observations of Mr. G. B. Buckton, 

 as to the more rapid development of Aphides on plants 

 of which the sap is sickly, and the amount of food to be drawn 

 from them insufficient, points to the reason of the increased 

 attack, but how this knowledge is to be utilised does not 

 appear at present. 



Amongst natural means of protection we have some help 



