Arsenic AT. Si'hay Extkkiments at 1<]esiv\bur(;. 363 



to see that lie coiistuiitly stirs llie 1i(]ni(1. Tjend iU'seiiat+> does not 

 spread over the sini'ace of the tiuit sufhciciiily uuirorinly to ii:ake so 

 comi)lete a coverino' that every codling* larva whieh attemjits to enter 

 the fruit is poisoned. It is likely to form concentrated llotches on 

 the surface of both leaves and fruit, n)aking it undesirably con- 

 spicuous on the fruit at the time the croj) is harvested. 



Lovett of ( )reo'on (6) has recently investigated the most i)7actical 

 s])readers that may be used with lead arsenate, and has determined 

 that the most desirable in lespect to cheapness, availability, compati- 

 bility, efficiency, and ease in preparation, in order of meiit, are cal- 

 cium casemate, g'lue, soap bark, and oil emulsion. 



Calcium caseinate, used in the Elsenburg experiments, was mnde 

 according to Lovett's foimula, ])y mixing- thoioughly 1 lb. oi hue 

 hydrated lime wiih 5 lb. of fine casein, obtained from the Aliwal 

 North creamery. A half-pound of the mixture was added slowly to 

 each 40 gallons of diluted lead arsenate in the spray tank, while being 

 vigorously stiired. A soapy solution resulted. 



Although the material appeared to spread well, forming* a more 

 uniform covering over the surface of the fruit than a solution of lead 

 arsenate and water only, results show that this spreader had practi- 

 cally no influence on the efficiency of lead arsenate in the control of 

 codling" nujth. Investigations of the effects of spreaders on the con- 

 tiol of codling ^^ill be continued next season with the object of improv- 

 ing the qualities of lead arsenate in water for the more effective con- 

 trol of this insect. 



AcKjNOWT EDCi ME.VTS. 



The writer desires to acknowledge the valuable suggestions given 

 by the Chief, Division of Entomology, in these experiments, and the 

 assistance of the horticulturist with reference to the use of the orchard 

 and spiay machinery. 



LrrEKAiruE Cited. 



(1) (d) "(higii! and Present Use of Some Insecticides and 

 Fangicides," by Sanders & Kelsall, in Proc. Nov. Scotia, Entomo- 

 logical Societv for 1918, No. 4, p. 69. {h) Quaintance, in Farmers' 

 Bull. No. i)08, U.S.]). A., i9LS. '(r) Tiovett in Oregon Bull. Xo. 169, 

 1920. 



(2) " Des Causes qui influent sur la Nocivite des Arsenicaux em- 

 ployes en Agriculiine," Progres Agric. Yitic. Mont])ellieT-, LXY, 

 No.'19, 1916, pp. 448-^52. 



(.",) CanadHin II oil., XLI, March 1918. 



{\) " 44ie Beneiicial Action of Lime in Lime-sulphur and Ticad- 

 arsenate Combination Sprav," bv liobinson in .//. Ec. Enf.. Xll, 

 No. 6, December, 1919. 



(5) " How the Fruit Grower may more effectively control Cod- 

 ling-moth," by F. W. Pettey, Jourtial of the Department of AqiicuJ- 

 tHi-c, S.A., October, 1921. 



(6) *' Insecticide Investigations," by Lovett, in Oregon Agr. 

 Exp Sta. liull. No. I(i9, 1920. 



