on sunny days with some wind* the mites crawl out of the 

 buds and stand erect on the outside of the bud. They then 

 either "jump " or are blown off by the wind, which is capable 

 .i-r' carrying them, probably, for a considerable distance. The 

 mites may also migrate by clinging on to insects which settle 

 on the affected bushes, and may travel for short distances on 

 the twigs by crawling. Naturally in this process of migration, 

 in which chance plays so large a part, very many of the mites 

 can never reach an appropriate food plant, but so enormous is 

 the number of mites produced Miss Taylor calculates that 

 under favourable conditions 1,000 mites may leave one bud 

 in an hour that sufficient reach fresh currants to carry on 

 the attack in spite of all losses. After migration, but before 

 the new buds are large enough to enter, the mites live at the 

 bases of the leaf stalks, between the developing buds and the 

 stem and among the young leaves at the growing points of the 

 shoots. When the buds are sufficiently large, that is to say 

 about July, the mites enter into them and reproduce, causing 

 the well-known " big buds." 



Natural Enemies. Black Currant Mites are attacked by 

 the larva of a minute parasitic insect (Tetrastichus eriophyes) 

 and by a parasitic fungus (Botrytis eriophyes). They are 

 also preyed on by other mites and insects. The reproductive 

 powers of the mite, however, appear more than sufficient to 

 counterbalance all losses in this manner. 



Methods of Control. 1. As has already been stated there 

 are no entirely successful measures for combating the Black 

 Currant Mite, and badly affected bushes should be grubbed, 

 up and burnt. In replanting it should be remembered that 

 adjacent red currants and gooseberries may be attacked; and 

 it is, therefore, better to choose a fresh site for the young 

 bushes. It should hardly be necessary to point out that stock 

 showing big buds should never, in any circumstances, be 

 purchased or planted, but experience shows that this error 

 is still sometimes committed. Similarly, cuttings should never 

 be taken from diseased bushes, unless they are required for 

 some special purpose, in which case they should be dipped 

 for ten minutes in water heated to a temperature of 115 F., 

 M treatment which appears to kill the mite in all its stages.! 



In order to obtain cuttings entirely free from mite, GoudeJ 

 recommends that soft cuttings should be taken in April May, 

 and after being dipped for one hour in a nicotine insecticide 

 (nicotine 98 per cent. ! oz., soft soap 4 oz., water 5 gallons) 

 and then rinsed in clear water, they should be stuck in a cold 

 frame. 



* Taylor, loc. cit., p. 121, et seq. 



I Spencer Pickering and F. V. Theobald. " Fruit Trees and their 

 Enemies, with a Snraying Calendar," p. 81. 



\ Goude, Jour. Mm. Agric.. p. 460, August. 1921. 



