376 MR. C. WARBURTON AND MISS A. L. EMBLETON ON 
Conclusions. 
The observations above recorded may be thus briefly sum- 
marized :— 
1. Of the mites surviving the winter, those which have not 
succeeded in entirely arresting the growth of the buds, but are 
driven out by their development before May, probably perish. 
2. There is a definite migration period, which takes place as the 
abortive buds dry up and become uninhabitable, the new buds 
being then ready fer the reception of the mites. In 1901 this 
period extended from the middle of May to the middle of June. 
Any mites found wandering in the autumn are probably of the 
nature of an overflow. 
3. Distribution is effected by (1) crawling, (2) adhering to 
insects, (3) leaping. 
4. There is a brief period when the total number of living mites 
is exceedingly few, the old buds being dead, while the emigrants 
which have attained the new buds have not yet increased to any 
considerable extent. This period in 190% coincided with the last 
week in June. ; 
5. The mites are unable to maintain life in the ground, nor do. 
they attack the roots. 
6. The red-currant plant can contract the disease, but does not 
appear to suffer greatly from it. The mites first appear on the ’ 
outside of the buds, penetrating inwards as they increase in 
number. 
7. Infested buds very commonly contain a Cecidomyid larva. 
which feeds on the mites. 
If the results thus obtained are trustworthy, certain inferences 
follow with regard to the treatment of the disease. The most 
important are these :— 
1. Any treatment of the ground under infested bushes is. 
unnecessary, as the mites do not live in the soil. 
9, Spraying in the early spring is only calculated to destroy 
mites which would perish in any case. 
3. The only time when spraying would be likely to prove: 
beneficial is at the end of May and the beginning of June, when 
it is undesirable on account of the blossom. 
4. The removal of all the new shoots from infested bushes at. 
the end of June, if practicable, would apparently clear the plants. 
of the disease. It is at all events important to remember that at. 
this time the pest is reduced to a minimum. 
