- 432 - 
OHLSRS, H. (1853) 
1925. DER KOHLTCEISSLING. Mitt. Beut . Landw. Gesell. 40: 646. 1925. 
Of the various insecticides which have "been tested in Denmark 
to control the larvae of "butterflies ( pieris b rassica e and P_. rapae ) , 
the following spray mixture has given the "best results: 2 percent 
nicotine ( 10-percent ) , 100 g. soap, and 10 1. water. 
LDJDBLOM, A. (1854) 
1928. INVESTIGATIONS ON INSECTICIDES. Meddel. Centralanst. Forsoksv. 
Jordbruksomradet [Sweden] No. 330, Landbruksent Avdel. No. 53, 
33 pp.,. illus. [in Swedish. Abstract in Rev. Appl . Ent. (A) 16: 
512-613. 1928.] 
Nicotine has about equal efficiency against the eggs of 
Pieris "brassicae L. whether pure or as a sulphate provided it is 
not influenced "by other components of the mixture. Pure nico- 
tine does not adhere well and an adhesive that does not lower its 
insecticidal power must "be combined with it. 
WILSON, H. F., and GENTNER, L. G- (1855) 
1918. THE IMPORTED CABBAGE TTORM IN WISCONSIN. Jour. Econ. Ent. 11: 
79-81, illus. [Abstract in Rev. Appl. Ent. (A) 6: 201. 1918.] 
Tobacco dust and lime apparently had no effect upon the 
larvae of the cabbage butterfly ( pieris rapae ) . 
HARGRSAVES, E. (1856) 
1924. THE ACTION OE SOME ORGANIC COMPOUNDS WHEN USED AS STOMACH POISONS 
EOR CATERPILLARS. Bull. Ent. Res. 15 (l): 51-56. 
A 1-percent nicotinic acid in a starch suspension killed only 
2 cabbage worms (pieris rapae L.) in 11 days (p. 53). A 1-percent 
nicotine (95 to 98-percent) emulsion killed only 4 cabbage worms in 
7 days and only 2 caterpillars of Spilosoma lubricipeda Esp. in 9 
days (p. 55) . 
HUCKSTT, H. C (1857) 
1934. FIELD TESTS ON LONG ISLAND OF DERRIS AS AN INSECTICIDE FOR THE 
CONTROL OF CABBAGE WORMS. Jour. Scon. Ent. 27: 440-445. 
The infestation was largely due to Pieris rapae , but later 
in the season Plutella maculipennis and Aut ographa brassicae became 
increasingly numerous. Talc, clay, and tobacco dust gave promise of 
being satisfactory diluents for derris dusts, which have given satis- 
factory results in the field for the control of cabbage worms. 
