28 



orchard spraying, miscible oil, kerosene oil emulsion and distillate oil 

 emulsion proved successful. Miscible oil was efficacious m the 

 strengths of 1 : 12 and 1 : 20, but 1 : 28 was only partially successful. 

 Kerosene emulsion succeeded in the strengths 10, 15 and 20 per cent. 

 Distillate oil emulsions at 3, 4| and 6 per cent, were efficacious, rather 

 more than one U.S. gal. of wash being required for yearling trees. 

 Carbon bisulphide, 20 cc. per tree, was injected in four places at from 

 8 to 12 inches from the trunlv with good results, but there is some 

 danger to the trees from the use of this insecticide. Treatnient of 

 infested trees in April or May is recommended, followed by examination 

 during July and August and, if necessary, by a further treatment 

 Manure round the trees helps to retain moisture and assists in combating 

 this Aphid on heavy soils. 



Hecke (G. H.). Mealybug Control.— Mf%. Bull. Gal. State Commiss. 

 Hortic., Sacramento, vi, no. 10, October 1917, p. 397. 



In consequence of the representations made by the citrus growers 

 of southern California, a sum of about £1,000 has been allocated by the 

 State Board of Control for the campaign against the citrophilus 

 mealv bug [Pseudococcus citroj)hilus]. This fund ^^ill be expended, 

 firstly, in work with natural enemies and the control of the Argentine 

 ant [Iridomyrmex humilis], and, secondly, in the demonstration ol 

 orchard control methods in co-operation with the Citrus Experiment 

 Station. 



Hundley (J. B.). Sulphur Injury in Yucaipa, 1917.— Mthly. Bull. 

 Cal. State Commiss. Hortic, Sacramento, vi, no. 10, October 1917, 

 pp. 402-407. 



The week 12th to 19th June, 1917, following the time when the 

 orchards of Yucaipa were extensively sprayed, was remarkable for a 

 heat wave which was unprecedented in recent years, the temperature 

 being 10 degrees higher than ever before known in the district, while 

 the heat was accompanied by a desert wind, both dry and hot. This 

 hot spell followed an exceptionally cold and rainy spring. The weather 

 conditions are emphasised because they seem to have been the main 

 factor in the spray-injury recorded. During the four years of work 

 against the codling moth [Cydia pomonelki], red spider and mildew, 

 the same sprays have been used without any injury to fruit ; in the 

 present case no injury was apparent until the fifth day of the hot spell, 

 which was from 10 to 20 days after the spray was applied. The leaves 

 were then observed to fall in large numbers, while the fruit, where 

 exposed to the sun, was severely scorched. The fruit continued to 

 develop round the scorched area, but was badly misshapen. A great 

 difference in susceptibility was noticed among the varieties of fruit. 

 Tables are given showing the compositions of the sprays used, and it 

 is evident that in practically every case where sulphur was used 

 injury resulted, the brand employed apparently making but little 

 difference. In no case was arsenate of lead, either with or without 

 soap, found to cause any injury. A study of the results of these sprays 

 indicates that there is danger in the use of sulphur in any form during 

 the growing period. Lead arsenate-sulphur-soap sprays seem fairly 



