1907.] The Black Currant Gall-Mite. 



593 



examined, but no mites were found, nor could any trace of big 

 buds be discovered on any of the bushes. 



In September buds were taken from the different bushes, 

 particularly those buds which appeared big or at all irregular 

 in shape. These were carefully treated by what is known 

 as the Nalepa and other methods ; numerous slides were 

 made and examined under the microscope, with the following 

 results : — 



Row I. — Out of a large number of buds examined, only two 

 were found containing mites ; in one there was a single im- 

 mature specimen, and in the other there were five examples, 

 also immature. 



Row 2. — Very few mites were found, but there were more 

 infected buds ; the largest number of mites found in a single 

 bud was seven. In all cases the mites were immature. 



Row 3. — Here the buds differed very little from those taken 

 from row 2, only the percentage of infected buds was slightly 

 greater. 



It is very evident that all the bushes benefited by the applica- 

 tion of the lime and sulphur. It would have been better, 

 however, had a little less lime been used (i part lime to 

 2 parts of sulphur Jias acted as well). In the case of those 

 bushes that received a single dusting, the big buds were con- 

 siderably reduced in number, not more than one-quarter of the 

 number being present in October of those present in February. 

 Where two dustings were given, a distinctly marked diminution 

 over those receiving one dusting was shown ; whilst where 

 three dustings were applied the mite was almost exterminated. 

 It must be borne in mind that neither a sprayfluid nor dry 

 application will reach the eggs in the buds, and it seems clear 

 that the number of adult mites which successfully migrated from 

 the old buds into the new ones was very small indeed. In all 

 cases the mites found were immature specimens. 



{U) Spraying zvith Lime and Sulphur, — The results obtained 

 by spraying were not so good as those by dusting. A larger 

 number of buds were affected, and in many of them there 

 were adult and immature mites and eggs. The differences be- 

 tween the one, two and three applications of the sprayfluid 

 were quite in keeping with those found to obtain where dusting 



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