292 



if the ground is permeable the larvae there are suffocated. During 

 the dry weather the pools diminish in size and the larvae near them 

 gather near the edges until finally the water is completely dried up, 

 when the dampest point swarms with them beneath the dead and dry 

 plant debris. It is an easy matter to throw some straw on this debris 

 a.nd set it on fire, thus killing enormous numbers. Those that are 

 too deep to be reached in this way may be killed by flooding or by 

 injecting carbon bisulphide. 



A very full description is given of various forms of apparatus for 

 injecting carbon bisulphide. 



Other insect pests of sugar-cane in Brazil include the P>Talid, 

 Diatraea saccharalis, ¥., and the scale, Pseudococcus citri, Risso, which 

 is combated with kerosene-soap emulsion. 



Uiiia Praga dos Laranjaes. [A Pest of Oranges.] — Bol. Minist. 

 Agric. Ind. e Conrm., Rio de Jmieiro, viii, October-December 

 1919 (1920), pp. 104-108. [Received 6th May 1920.] 



Attention is drawn to the estabhshment of the scale, Icerya piirchasi, 

 in the State of S. Paulo where it promises to become a serious danger 

 to fruit growing. The necessity for a proper quarantine service is 

 emphasised, if the introduction of other pests is to be prevented. 



Ramsay (A. A.). The Compositions of various Lead Arsenates. — 

 Agric. Gaz. N.S.W., Sydneij, xxxi, Part 3, March 1920, pp. 208- 

 212. 



The lead arsenate that remains in suspension longest is the most 

 efficacious for spraying purposes. The results of tests made with 

 various commercial brands are discussed and illustrated by a graph. 



Ramsay (A. A.). A Dry Form of Lime-Sulphur. — Agric. Gaz. N.S.W., 

 Sydney, xxxi, Part 3, March 1920, p. 216. 



The preparation sold under the name of B, T. S., for use in all 

 cases where Hme-sulphur spraying is desired, has been analysed in 

 solution. It is recommended by the manufacturers for use at the 

 rate of 12 to 14 lb. per 50 gals, water for dormant trees and at 1 to 4 lb. 

 in the same quantity of water for trees in foliage. It appears to be 

 a preparation of barium tetrasulphide of about 88 per cent, purity. 



Tests in the laboratory showed that there is greater decomposition 

 in the more dilute solutions, and it is also probable that the length of 

 time the solutions are left standing might also affect the results 

 obtained in spraying in the field. 



Favor (E. H.). Spraying Machinery for the Citrus Grove. — Florida 

 State Hortic. Soc. Qtrly., De Land, Proceedings 32nd Ann. Meeting, 

 1919, pp. 53-57. [Received 8th May 1920.] 



This paper emphasises the importance of spraying in Florida, 

 showing how Florida oranges are at a disavantage on the market, 

 owing to their poor external appearance. Types of sprayers are 

 considered, with the relation between the cost of the machine and its 

 earning power, the power and fineness of the spray being the important 

 points for efficiency. 



