590 



The Black Currant Gall-Mite. [Jan., 



been experimented with both at home and abroad with a view to 

 exterminating this and other species of mites. Mr. E. J. Lewis, 

 after a series of experiments in 1900 and 1 901, writes,* "the 

 results of these experiments . . . show that fumigation will, in 

 most cases, diminish the ^attack by destroying a great number 

 of the mites, but that apparently it has no effect upon the eggs, 

 and will not entirely get rid of the disease. . . It is doubtful if 

 any alteration in the amounts of the chemicals used or in the 

 length of time during which the bushes are under treatment 

 would be able to effect a permanent cure." 



This is entirely in accord with my own experiments, and with 

 the opinions of all whom I have known to try fumigation. 

 Further, it may be pointed out that the fumigation of bushes 

 covering large areas is only carried out with great difficulty ; 

 most of the experiments made have been upon cuttings and 

 young bushes before being planted out, but cuttings should not 

 require fumigation, for surely no responsible person will take 

 cuttings from infested bushes, or buy plants without knowing 

 they have been examined by an expert and pronounced free 

 from disease. Mr. Warburton, in his annual Report for 1902,! 

 writes that great benefit would accrue both to sellers and 

 buyers of black-currant cuttings if those who supply them 

 would have their crops examined by an expert to determine 

 whether the mite is present or not. A certificate of freedom 

 from the disease would be of considerable value to the possessor 

 of a fine crop, and buyers would be only too glad to be sure 

 that the cuttings supplied to them came from a pure stock. 1 

 would suggest, in the first instance, that any who believe that 

 the disease is not present in their plants, and who are willing 

 to supply cuttings, should have their fruit gardens visited by an 

 expert and reported on, and that those . . . who require cuttings 

 should insist upon some attestation of the purity of the plants 

 from which they are taken. In this manner much would be 

 done to gradually stamp out the disease." This suggestion I 

 most heartily endorse, as the importance of obtaining pure stock 

 cannot be over estimated. 



(ii.) Sprayfiuids. — The only time sprayfluids can be used to 



* Op. cil., p. 26. 



i Journal, Royal Agricultural Society, 1902, vol, 63, p. 305. 



