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FROST, S. 17., and HORSFALL, J. L. / (2023) 
1925. T70EK YjITH INSECT PESTS BY THE PENNSYLVANIA STATION. Pa. Agr, 
Expt. Sta. Bull. 196, pp. 32-33. [Abstract in Expt. Sta. 
Record 54: 352-353. 1926.] ■ 
In a search for a powdered material to replace soap as a 
spreader in a liquid nicotine spray for plant lice, four 
materials were compared with fish-oil soap. When used without 
lime, none of the mixtures gave as high a kill as fish-oil soap 
and nicotine. 
Various soil fumigants were used in lettuce cold frames for 
control of millipedes. Nicotine sulphate (1:500) resulted in 
an increased stand. A 2 percent home-mixed nicotine dust worked 
into the soil one week before the boxes were seeded gave good 
results. 
LABO, A. (2024) 
1927. INSECTICIDES IN FLORICULTURE. Riv. Ital. Essenze Profumi 
9:19. [In Italian. Abstract in Chem. Abs. 21:2043. 1927.] 
Discusses use of nicotine salicylate, tobacco extract, and 
tobacco vapors against insects which damage flowers. 
TROPPkANN, XI. (2025) 
1927. PEST CONTROL. Leipzig, 440pp., illus. [In German.] 
This book (Schadlingsbekampfung) briefly discusses nicotine 
(pp. 185-169, 270-272) from the chemical and insecticidal view- 
points. The nicotine content of air dry tobacco varies accord- 
ing to the kind, climate, soil, fertilizer, and way of planting 
from 0.5 to 10 percent. For the manufacture of home-made tobacco 
extract Peters soaked 5 kg. of finely cut dry tobacco leaves three 
times in 33 1. of water, each time for 24 hours. The nicotine thus 
extracted contains partly free nicotine, partly nicotine compounds 
with organic acids. It is usually treated with sulphuric acid and 
is put on the market as nicotine sulphate. A tobacco extract of 
8 to 10 percent nicotine is usually used in Germany, but in the 
United States an extract known as "Black Leaf 40" and containing 
40 percent nicotine is commonly used for insecticidal purposes. 
Nicotine is used in the control of aphids, caterpillars, sawfly 
larvae, microlepidopterous larvae, various species of Hempitera 
(loaf sucking bugs), etc., commonly in conjunction with soap solu- 
tions at the ratio of 1 to 1.5 kg. tobacco extract (10-percent), 
1 to 2 kg. soft soap, and 100 1. water (pp. 185-189). Powdered 
tobacco and nicotine dusts and their uses are also discussed 
(pp. 270-272). 
