288 



Diahrotica spp. (cucumber beetles). These insects show a great differ- 

 ence in their susceptibihty to nicotine, the range being from a 1 per 

 cent, dust, which gives a very good control ior Chromaphis juglandicola, 

 to the 10 per cent, mixture. 



This dust may be mixed with sulphur, lead arsenate, dry pulverised 

 Bordeaux mixture, or with any dry fungicide or insecticide for the 

 control of more than one pest at one application. 



DE Ong (E. R.). Selection and Treatment of Waters for Spraying 

 Purposes with especial reference to Santa Clara Valley. — Calif. 



Univ. Agric. Expt. Sta., Berkeley, Bull. 338, December 1921, 

 pp. 301-314, 2 figs. [Received 27th March 1922.] 



During the summer of 1919 a suryey was made to ascertain the 

 degree of hardness of waters in various parts of the Santa Clara 

 Valley, California, the results of which are here described. 



The California waters have an unusually high chlorine content, 

 and this may account for the injury occurring where acid lead arsenate 

 has been used in sprays. Basic lead arsenate should be substituted 

 for use with such waters. 



Canela (P. F.). Sobre la Presencia de una Plaga en los Frutales de 

 San Luis. — Bol. Mi nisi. Agric. Nac, Buenos Aires, xxvi, no. 3, 

 July-September 1921, pp. 253-256. [Received 27th March 1922.] 



Fruit-trees in San Luis, particularly peaches, damsons and plums, 

 are seriously attacked in many instances by the Scolytid, Scolytus 

 rugulosns, Ratz., which is spreading to an alarming extent. As many as 

 five generations may be produced in a favourable season. The larvae 

 of the last generation remain in the galleries between the bark and the 

 wood, pupating there in the following spring and emerging as adults 

 about two weeks later. The females, after fertilisation, immediately 

 begin to construct fresh galleries in the young branches, where the 

 various generations develop. The remedies recommended are those 

 generally used for this borer [R.A.E., A, ii, 164]. Clean cultivation 

 and early pruning are accessory measures. 



LicHTENSTEiN (J. L.). La Bruchc des Haricots {Laria ohtecta, Say). — 

 Progres Agric. & Vitic, Montpellier, Ixxvii, no. 13, 26th March 

 1922, pp. 298-300. 



Bruchus {Laria) obtectus. Say, is recorded as causing serious damage 

 to beans in the neighbourhood of Toulouse. Infestation appeared to be 

 less severe in beans planted 2nd July than in those planted earlier, 

 and it is thought that the judicious choice of the date for planting 

 may prove a useful preventive measure. 



SURCOUF (J. M. R.). Note sur une Maladie du Palmier : Le Doud. — 



Bull. Soc. Hist. Nat. Afr. Nord, Algiers, iii, no. 2, February 

 1922, pp. 34-35. 



The date palm disease known as " Doud " is considered to be due 

 to the lesions caused by Phyllognathus silenus and Oryctes hispinosus, 

 both species being abundant in Algeria, during the adult and larval 

 stage, especially the latter. The disease may be the direct result of 

 injury or due to secondary infection of a bacterial nature [cf. R. A.E.. 

 A, X, 271]. 



