Derris as an Insecticide 



183 



To facilitate the handling of a product which might be used as a 

 proprietary insecticide, an alcoholic extract was incorporated into a 

 soft linseed-oil soap at the rate of i gm. of extract to 4 gm of soap. 

 This product was later dissolved in water in the proportion of i to 2,400, 

 which would be equivalent to about i pound of powder to 200 gallons of 

 soap solution. All of the small fall webworms sprayed with this solution 

 died, but none of the controls sprayed with soap solution of the same 

 strength died. 



Table II. — Effects on the honeybee of eating extracts and powders of Derris sp. {probably 



D. elliptica) 



No. of 

 extract 

 or pow- 

 der 

 used. 



246 

 247 

 248 

 249 

 250 



251 

 252 



253 

 254 



240 

 241 

 242 

 243 

 244 

 245 



258 



260 

 261 

 264 



266 



259 



262 



263 

 265 



Extracts, powders, and controls. 



Petroleum-ether extract (no heat used) . . 

 Petroleum-ether extract (heat used) . . . 



Ether extract (no heat used) 



Ether extract (heat used) 



Chloroform extract (no heat used) 



Chloroform extract (heat used) 



Alcoholic extract (no heat used) 



Alcoholic extract (heat used) 



Water extract (heat used) 



Control , alcohol in honey 



Control, honey alone 



Powder exhausted with petroleum ether 



Powder exhausted with ether 



Powder exhausted with chloroform .... 



Powder exhausted with alcohol 



Powder exhausted with water 



Powder not exhausted with any solvent. 



Control, wheat flour in honey 



Powder exhausted with petroleum ether 

 Powder exhausted with above solvent 



and ether 



Powder exhausted with above solvents 



and chloroform 



Powder exhausted with above solvents 



and alcohol 



Powder exhausted with above solvents 



and water 



Control, wheat flour in honey 



Control, honey alone 



Petroleum-ether extract from original 



powder 



Ether extract from above powder (2d 



extraction) 



Alcoholic extract from above powder 



(3d extraction) 



Water extract from above powder (4th 



extraction) 



Control, alcohol in honey 



Number 

 of bees 

 tested. 



150 

 150 

 150 



150 

 150 

 150 

 150 

 150 

 150 



150 

 100 

 100 

 100 

 100 

 100 

 100 

 100 

 100 



100 



ICO 



100 



100 

 100 

 100 



100 



100 



100 



100 

 100 



Percentage of bees dead within- 



48 hours. 



After eat- 

 ing ex- 

 tracts and 

 controls. 



67 



73 



48 hours. 



7 days. 



After eating powders 

 from which one or 

 more extracts had 

 been removed, and 

 controls. 



ICO 



4 

 2 



6 



94 



100 



73 



16 



18 



16 

 IS 



a This powder emitted an odor resembling that from petroleum ether; the bees ate very little of the honey 

 containing it, and therefore most of them probably died for lack of suitable food. 



