350 



the end of May onwards, and those that descend the tree to the roots 

 in the autumn. These treatments should control all the commoner 

 pests of apple, including Aphids, Capsids, caterpillars and apple-sucker 

 [Psylla 7rmli]. 



Lees (A. H.). The Control of Logan Beetle by Cultivation. — Univ. 

 Bristol : Ami. Rept. Agric. & Hortic. Research Sta., Long Ashton, 

 Bristol, 1919, pp. 48-49. [Received 17th June 1920.] 



The loganberry beetle [Bytiirus tomentosus'] is probably the worst 

 pest of loganberries and is very difficult to deal with, as most of its 

 adult hfe is passed within the ground, while the larval stage is spent 

 within the berry. The adults emerge from the soil over a long period, 

 so that in attempting to control by spraying several operations are 

 necessary. A successful spraying method has been evolved {R.A.E., 

 A, vi, 424], but is too expensive to be thoroughly satisfactory. It has 

 been observed, however, that berries growdng in well cultivated soil 

 suffer far less than others, and experiments have therefore been con- 

 ducted in which cultivation was practised in spring only, in autumn 

 only, and in both spring and autumn. The results showed a marked 

 decrease of infestation where any cultivation was done, but the differ- 

 ence between the variously treated rows was not sufficient to draw any 

 definite conclusion, and the experiments must be continued for a 

 further period. 



Lees (A. H.). Big Bud. — Univ. Bristol : Ann. Rejjt. Agric. & Hortic. 

 Research Sta., Long Ashton, Bristol, 1919, pp 50-56. [Received 

 17th June 1920.] 



The big bud mite [Eriophyes ribis] passes the greater part of its Ufe, 

 roughly from June to March, in the interior of the buds of black 

 currant bushes. During the rest of the year it is migrating from the 

 previous year's buds and is seeking entrance to the buds of the current 

 year. Consequently though spraying operations have met with some 

 success [R.A.E., A, vi, 425], they cannot be considered a practicable 

 method of control. Several varieties have been introduced as resistant 

 to big bud but all have eventually been more or less attacked [R.A.E., 

 A, vi, 480]. It is probable that chmate has a good deal to do with the 

 possibihty of formation of big bud ; a moist season, by prolonging the 

 growing season of the bush, increases the food-supply of the growing 

 points and thus allows the mite to form a big bud instead of a killed 

 bud. While increase on any one bush may be quick or slow according 

 to external conditions, increase from bush to bush is governed by 

 chance and is generally slow. Experiments in control have given 

 largely negative results. The difficulty in spraying during the migrating 

 season is that it is impossible to destroy the som:ce of infection 

 in the big buds of the previous year, and that spraying must be very 

 frequent if it is to prevent any mites reaching the buds of the current 

 year. 



Investigations to test the action of hme-sulphur are described. 

 The conclusion is drawn that in the locality of Long Ashton hme- 

 sulphur at the rate of 1 in 16 or 1 in 12, apphed as soon as the first 

 leaves are as big as a sixpence, results in a considerable decrease in the 



