562 



in one case and proved to be 9J days. Some bait-traps appear to be 

 specially attractive to the moths and investigation of the reason would 

 be amply repaid. In 1914, insecticide treatment was carefully carried 

 out, but lack of labour permitted only one application, whereas two are 

 necessary for practical results. 



Semichon (L.). L'§conomie dans les soufrages et les sulfatages. 



[Economy in spraying with sulphur and copper sulphate.]- — Rev. 

 Vitic, Paris, xlii, no. 1093, 10th June 1915, pp. 483-485. 



To spray both efficiently and economically, hot neutral copper sprays 

 should be applied every twenty or twenty-five days. In the intervals, 

 the vines should be dusted with sulphur mixed with sulphated talc or 

 with sulphur and copper hydrate. An excellent mixture consists of 

 sulphur and cupric talc in ecpial parts. Talc usually contains 10 per 

 cent, of carbonate of lime, and if 10 per cent, of finely ground copper 

 sulphate is added, the acidity of the cojDper sulphate is neutralised by 

 the lime. This prevents scorching and the cupric precipitate of 

 hydrate and carbonate is far less soluble than the sulphate and protects 

 for a longer time. These facts should be borne in mind when selecting 

 a cupric powder. The method of treatment given above will effect a 

 saving in sulphur and copper sulphate, whilst acting Avith great 

 efficiency against mildew, oidium and injurious insects, especially 

 Clysia ambiguella and Polychrosis botrana. Four sprayings and four 

 dustings will require 83 lb. of copper sulphate and 1141b. of sulphur 

 per acre. 



Chauvigne (A.). Les sulfatages chauds centre la Cochylis. [The 

 control of Cli/sia ambiguella wnth hot cupric spray solutions.] — 

 Rev. Vitic, Paris, xlii, no. 1094, 17th June 1915, pp. 503-505. 



It is stated that although M. Semichon's methods and formulae for 

 the application of hot spray solutions [see this Review, Ser. A, ii, p. 685] 

 were adhered to in a series of trials, the results invariably proved 

 inefficacious. It would appear that a temperature of at least 131° F. 

 is necessary and this is apparently unattainable with the methods in 

 question, at least in a practical manner for areas of medium or large 

 size. The egg and larva of Clysia ambiguella only seem to be affected 

 by dry heat, so that water, even if at a temperature of 131° F., may 

 not be harmful to the insects. 



Gastine (G.) & Vermorel (V.). Destruction des parasites des plantes 

 par la chaleur humide. [The destruction of plant pests by 

 damp \iedit.'\—Rev. Vitic, Paris, xlii, 210. 1095, 24th June 1915, 

 pp. 521-526. 



The authors refer to their experiments in control by means of steam ; 

 these were carried out in 1902 and published at that time. It was 

 first ascertained that damp heat would kill most injurious insects in 

 a much shorter time than was required to damage the tissues of the 

 most sensitive plants, such as the young leaves of the vine. Diagrams 

 are given to show this. In practice, a bell was placed over the vine- 

 stock and steam from a small boiler was conducted to it and caused to 

 issue against its imier surface. In condensing, the steam warmed the 



