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HEAD LEI, T. J., ET AL. (2294) 
1922. REPORT OF THE DEPARTMENT OP ENTOMOLOGY. N. J. Agr. Expt. Sta. 
Kept. pp. 411-475, illus. [Abstract in Expt. Sta. Rec. 51: 658-659. 
1924.] 
This rep»rt includes "A Study of Dust Carriers for Nicotine" by 
tf. Rudolfs (pp. 445-449). Nicotine dusts composed of Milltown ball 
clay No. 9 and ground burned lime, as a carrier will kill a slightly 
higher percentage of the pink and green aphids ( Macro siphum solanifolii ) 
of the potato end tomato than can be destroyed with the regular nicotine 
soap rnd water plant-louse spray. Dolomite was the best carrier found 
in this study. 
HEADLES, T. J., and RUDOLFS, VJ. (2295) 
1922. SOME FURTHER EXPERIENCE T7ITH CONTACT DUSTS. Jour. Econ. Ent. 15: 
75-81. [Abstract in Rev. Appl. Ent. (A) 10: 304-305. 1922.] 
The two great disadvantages of nicotine delivered as a dust are 
that rain falling within the first 72 hours seems to reduce if not 
entirely stop its action and the cost is greater than that of a sub- 
stance that is as effective when delivered in a spray form. A 2 
percent nicotine-clay-calcium oxide dust kills 87 percent of the 
pink and green aphids ( Macrosiphum solanif o lii) while under the' same 
conditions the spray will kill slightly over 85 percent. A 1 percent 
nicotine calcium oxide dust kills nearly 84 percent. The maximum 
efficiency of the dust is reached between 24 and 72 hour's after applica- 
tion, while the spray reaches a high point of toxicity within 24 hours. 
The improvement, of the nicotine dust is to be sought in the more 
rapid evolution of the 2 percent or less of nicotine which is within 
the range of reasonable practice. 
PARROTT, P. J. (229 6) 
1922. CONTROL OF SUCKING INSECTS BY DUSTING. Jour. Econ. Ent. 15: 
82-85. [Abstract in Rev. Appl. Ent. (A) 10: 305-306. 1922.] 
Dusting mixture containing 0.25, 0.5, 1.0 and 2.0 percent 
nicotine proved toxic to the apple rtdbug ( Lygidea mendax Reut.) 
and the dark redbug ( He t e r o c o rdy lu s m alinus Reut.). Spraying with 
nicotine sulphate, 1 to 800, plus 6 lb. soap to 100 gal. gave good 
control of the currant aphid ( Myzu s ribis L. ) . A 90 to 10 sulphur- 
lead arsenate dust carrying 0.5, 1.0 or 2.0 percent nicotine also 
afforded efficient protection. 
The formula advocated against the cabbage aphid (B revicoryne 
( Aphis ) brassica e) and cabbageworm ( Pieris rapae L. ) is nicotine 
sulphate 5 lb. powdered lead or calcium arsenate 15 lb. and hydrated 
lime 80 lb. 
c rosiphum solanif olii Ashm. (potato aphid) is the most dif- 
ficult species to control. Dehydrated copper lead arsenate containing 
