Insects, etc., Injurious to the Vine. 485 



"Result. Mealy bug destroyed., No injury to vines. A few 

 appeared in the autumn and a second fumigation was given, with the 

 same success as in the previous case. 



" VINERY C. Capacity, 1,990 cubic feet. 



Early variety. Treated when grapes the size of peas. 

 Cyanide, 6 oz. ; acid, 9 oz. ; water, 15 oz. 



Temperature, 65 F. ; weather very sultry at time. Time, 

 40 minutes. 



" Result. Grapes browned and killed. Entire crop lost. Eoliage 

 uninjured. Mealy bug destroyed. The vinery was kept on the 

 cool side, plenty of air 

 given, and splendid growth 

 and promise of fruit for 

 next year was obtained. 



" A few mealy bugs ap- 

 peared in October. Fumi- 

 gation was repeated. All 

 the bugs were destroyed. 

 The season had so far ad- 

 vanced, however, that eggs 

 were to be found on the 

 shoots. 



" Painting the rods with 

 the winter alkali wash in 

 spring and a fumigation 



i .i_' i i [</ G. Blakey. 



before the bloom appears PIG _ 314A ._ MEALY BUG (Dactylopius lo>igispimts ). 

 have been decided upon." (x s.) 



The result of these experiments led Cousins to summarise treat- 

 ment as follows : 3 oz. cyanide, 5 oz. acid, 8 oz. water per 1,000 

 cubic feet, either before the vines bloom or when grapes are colouring 

 or after the crop has been gathered. Avoid fumigation when the 

 vines are in bloom or before the grapes have commenced to ripen. 



We may take the latter precautions to apply generally. 



Considerably less of the chemicals have been used with success. 

 For instance, Miss May Crooke, experimenting at Bredon's Norton 

 School of Gardening (2), found that 3 oz. of 98 p.c. potassium 

 cyanide, 1^ oz. fluid sulphuric, and 4 oz. of water killed all the 

 mealy bugs in 1,920 cubic feet of space. 



At Swanley College a large vinery of 17,750 cubic feet space was 

 fumigated in December for forty-five minutes with 1^ oz. sodium 



