216 



to make 100 U.S. gals. This spray has been used with success for 

 more than a year, and can be apphed to a large variety of plants during 

 the winter season without injury. 



Soapjpowder emulsion is composed of distillate emulsion, 5 U.S. 

 gals. ; soap powder, 10 lb. ; water to make 100 U.S. gals. This 

 spray is however more injurious to the foHage than the preceding one, 

 and may even cause severe dropping of the leaves unless applied under 

 favourable climatic conditions. 



Water sprayed imder pressure is being increasingly used with some 

 measure of success, this depending on thorough and repeated appli- 

 cations. 



The reduction of the numbers of this pest by natural enemies has 

 already been dealt with [see this Review, Ser. A, v, p. 266]. The 

 necessity for measures against Iridomyrmex humilis, Mayr (Argentine 

 ant) in this connection has also been noticed [see this Review, Ser. A, 

 V, p. 422]. 



The prevention of the spread of these scales by means of infected 

 picking boxes, sacks and gloves, could be effected by fumigating all 

 boxes with hydrocyanic acid gas, and by dipping sacks, gloves, etc. 

 into gasoline for five minutes to destroy adhering insects or their eggs. 



Morgan (A. C). Tobacco Hornworm Insecticide. Recommendations for 

 Use of Powdered Arsenate of Lead in Dark-Tobacco District. — U. S. 



Dept. Agric, Washington, D.C., Farmers' Bull. no. 867, August 

 1917, 10 pp., 4 tables. [Received 7th March 1918.] 



This bulletin supersedes a former one, which has already been 

 noticed [see this Review, Ser. A, ii, p. 601]. It contains in addition, 

 in tabular form, a comparison of results obtained in 1916 in Kentucky 

 and Tennessee by the use of Paris green and powdered lead arsenate 

 against the caterpillars of Protoparce (Phlegethontius) sexta, Joh., and 

 P. quinqiiemaculata, Haw., the lead arsenate having been found prefer- 

 able in many respects. 



Sasscer (E. R.) & Borden (A. D.). Fumigation of Ornamental Green- 

 house Plants with Hydrocyanic-acid Gas. — U.S. Dept. Agric, 

 Washington, D.C., Farmers' Bull. no. 880, October 1917, 20 pp. 

 [Received 7th March 1918.] 



The subject matter of this bulletin has already been noticed [see 

 this Review, Ser. A, v, p. 244]. 



Back (E. A.). The Silverflsh, or '* Slicker," an Injurious Household 

 Insect. — U.S. Dept. Agric., Washington, D.C., Farmers' Bull, 

 no. 902, October 1917, 4 pp., 1 fig. [Received 7th March 1918.] 



This matter contained in this bulletin which supersedes a former 

 one has already been noticed [see this Review, Ser. A, iii, p. 587]. 



YoTHERs (W. W.). Some Reasons for Spraying to Control Insect and 

 Mite Enemies of Citrus Trees in Florida.— C/. S. Dept. Agric., 

 Washington, D.C., Bull. no. 645, 26th January 1918, 19 pp. 

 [Received 4th March 1918.] 



The adoption of a system of spraying for the improvement of 

 orchard conditions is only now beginning to be tested by growers. 



