- 551 - 
The pink and grce potato aphid ( Macro sip ham solanif olii Ashra.) 
can he controlled by spraying with nicotine soap and water or with 
bordeaux mixture containing 1 gal. 40 percent nicotine sulphate in 
500 gal. of the spray, or by dusting with 30 lb. of 1 l/2 percent 
free nicotine dolomite dust or 2 to 2 1/2 percent nicotine sulphate 
dolomite lime dust per acre. For a 2 percent nicotine dust the 
materials are hydrated lime, ground dolomite (magnesium limestone) 
100 mesh fine and 40-percent nicotine sulphate in the proportions 
57: 19: 4. 
BEADLES, T. J. (2311) 
1924. REPORT OF THE DEPART! SENT OF ENTOMOLOGY. N. J. Agr. Expt. Sta. 
44th Ann. Rept. 1923, pp. 265-337, illus. 
In a report on the codling moth, curculio , aphids, and pear 
psylla (pp. 269-284) , 40-percent nicotine was used in many of the 
sprays. 
In a report on nicotine dust (pp. 286-293), it is believed 
that the best average results are likely to follow the use of 
nicotine dust, the nicotine of which is drawn from free nicotine 
sources (p. 293) . 
HEADLSE, T. J., and RUDOLFS, W. (2312) 
1924. SOME FURTHER FACTS RELATIVE TO THE PRINCIPLES UNDERLYING THE 
MAKING AND USE OF NICOTINE DUST. N. J. Agr. Expt. Sta. Bull. 
400, 44 pp., illus., New Brunswick. [Abstract in Rev. Appl. 
Ent. (A)" 13: 386-387. 1925.] 
"Since the authors' previous paper (Rev. Appl. Ent. (A) 12: 
31) further observations have been made on the evolution of nicotine 
gas from dusts under field conditions and its effects on Illinoia 
( Macro siphu m) pisi , and also on the Influence of temperature, 
relative humidity, size of particle of the carrier and thickness of 
nicotine layer on the particles. For the field tests a special 
apparatus had to be constructed, details of which are described. 
The dusts were applied with a Leggett traction duster s.t the rate 
of 45 lb. per acre on rows of peas that were in practically full 
blossom. Throe nicotine dusts were used: ground magnesium lime- 
stone (dolomite) impregnated with sufficient free nicotine to insure 
a 1 l/4 percent actual nicotine content, and "Black Leaf F " and 
"Black LQaf F ", guaranteed 1 l/4 and 2 percent actual nicotine content 
respectively. J An extremely rapid delivery of nicotine gas is 
more effective than one that is slower but longer continued. 
A temperature of 70° F. or higher is necessary to promote a rapid 
evolution of nicotine gas from the dusts under field conditions; 
belovr this point evolution decreases and at 50 F. there is practically 
no evolution whatever. The escape of the gas from the free nicotine- 
dolomite dust is materially more rapid than from the Black Leaf 
products. At 70° F. or above, free nicotine dolomite dust, even when 
applied at the rate of 50 lb. per acre, evolves practically all of its 
nicotine in 6 hours. The great bulk escapes in the first three hours. 
