- ol'J - 
Experiments are described in which nicotine solution was applied 
to the tips of the .antennae and wings of "butterflies in order to 
'study its effect on the nervous system. The action, which is con- 
vulsive, seems to "be localized in the ganglia of the central nervous 
system, poison applied to the antennae affecting the cerebral ganglia 
first . The toxic action is proportionately greater as the temperature 
is higher. 
RICHARDSON, C H., and SHEPARD, H. H. (2152) 
1930. THE EEEECT OF HYDRO GEN- 1 Oil CONCENTRATION ON THE TOXICITY OE 
NICOTINE, PYRIDINE AND METHYLPYRROLIDINE TO MOSQUITO LARVAE. Jour. 
Agr. Res. 41 (4): 337-348, illus. [Abstract in Rev. Appl. Ent . (B) 
19: 29-30. 1931.] 
The speed of toxic action of these substances to the larvae of 
Culex pipiens L. was directly related to the concentration of the un- 
dissociated molecules. It is believed that the toxicity results 
largely from the penetration of the molecules into the body through 
the wall of the alimentary tract. Nicotine ions are somewhat toxic 
"but much lees so than nicotine molecules, previous writers have ex- 
plained the greater toxicity of nicotine over nicotine sulphate on 
the "basis of the greater volatility of the former. In this study 
it was shown that the free base in solution is also much more toxic 
than nicotine sulphate. 
STELLT7AAG-, F. (2163) 
1930. TOXICITY AID TOXIC VALUE OE INSECTICIDES. PART III. THE GENERA 
TECHNIQUE OP DETERMINATION OE PHYSIOLOGICAL VALUE (CONCLUSION). 
Anz. Schadlingsk. 6 (6): 64-63, illus. [in German. Abstract in Rev. 
Appl. Ent. (A) 18: 525. 1930.] 
It is pointed out that attention should be paid to external 
factors, such as temperature and light. Silkworms ( Bombyx mori L.) 
died in 90 to 140 minutes at 55.6° F. and in 7 to 13 minutes at 
89.6° F, when kept in glasses containing filter paper moistened 
with '0.0004 percent pure nicotine. 
JANCKS, 0. (2154) 
1931. CONTRIBUTIONS TO THE CONTROL OF PESTS BY THE INTERNAL TREAEJENT 
OF PLANTS. 1ST COMMUNICATION. Ztschr. Angew. Ent. 18 (2): 275-318, 
illus. [In German. Abstract in Rev. Appl. Ent. (A) 19: 725-725. 
1931. j 
Investigations with sucking and chewing insects have been made ai 
Naumburg to test the value of nicotine and other substances as internal 
treatment of plants against insects. Doses tolerated by the plants were 
also tolerated by the insects, and a satisfactory effect on the latter 
almost always involved injury to the former. Nicotine, absorbed by 
grape-vine shoots and found in the leaf-tissue, did not penetrate the 
tissue of Phylloxera leaf-galls in 7 days, so that the aphids feeding 
in the .rails were unaffected. 
