18 



BULLETIN 1201, U. S. DEPARTMENT OF AGRICULTURE. 



Table 5. — Comparative results obtained by spraying Macrosiphum sp. A with 

 alcoholic and benzene extracts derived from "cube," derris, etc. — Continued. 





Aphids sprayed with alcoholic extracts. 



Aphids sprayed with benzene extracts. 



Preparation. 



Num- 

 ber of 

 sets. 



Esti- 

 mated 

 num- 

 ber of 

 indi- 

 vid- 

 uals. 



Percentage of aphids 

 dead within — 



Percentage of aphids 

 dead within — 



Num- 

 ber of 

 sets. 



Esti- 

 mated 

 num- 

 ber of 

 indi- 

 vid- 

 uals. 





6 

 hours. 



1 

 day. 



2 



days. 



3 



days. 



6 

 hours. 



1 

 day. 



2 

 days. 



3 



days. 



Control, solvent 

 +soap+water 

 (4+2+100)... 



1 



1 

 3 

 2 



500 



500 



1,500 



1,000 



5 

 5 

 5 

 5 



15 

 15 

 12 

 10 



15 

 15 

 13 

 12 



15 















Control, solvent 

 + soap + water 

 (2+2+100)... 















Control, solvent 

 + soap + water 

 (1+2+100)... 



Control, solvent 

 + soap + water 

 (1/2+2+100).. 





10 

 5 



10 



15 



15 

 15 





1 

 1 



500 

 500 



Table 6. — Comparative results obtained by spraying 11 species of aphids with 

 alcoholic extracts derived from " cube," derris, and pyrethrum, and with JfO 

 per cent nicotine sulphate, mixed with soap solution and kerosene emulsion. 





Preparation. 



Percentage of aphids dead within 24 hours. 



6 



ft 



a 



03 

 EC 



a 



id . 

 ft«3 



o ft 

 o 



a 



a 



3 



d . 



fta> 



£2 



o 



03 



d'3 

 ft o 



s| 



03 M 



a 



d 



■d . 

 ftO 



o ft 



o 



03 



< 



ft 



3 

 & 

 < 



a 



3 

 ft 



< 



ft 



3 



ft 



6 



03 



ft 

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 3 

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03 



d.-i 

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8% 



d 

 ft 



3 

 p. 

 < 



pS 



d 



3 

 3 



509 



Alcoholic extract+soap+ 



8+4+100, Pyrethrum. 

 4+4+100— 







95 



90 

 98 

 95 



















509 























507 

























506 



"Cube" 























509 



4+2+100— 



Pyrethrum 



98 

 100 

 100 





















507 























506 



"Cube" 























506 



2+4+100— 



"Cube" 









95 

 95 

 95 



100 

 95 

 95 













507 



Derris 





















509 























509 



2+2+100— 



95 

 100 

 100 



100 

 100 

 76 



60 

 98 

 100 



100 

 97 

 40 



82 

 99 



99 

 62 



97 



97 



92 

 100 

 100 



100 

 100 



89 

















507 





















506 



"Cube" 



50 



90 







90 

 40 











506 



1+2+100— 



"Cube" 







95 









507 



















509 



Pyrethrum 



3/4+2+100— 









































509 



Pyrethrum 





507 























506 



"Cube".... 























506 



1/2+2+100— 



"Cube" 



100 

 95 



86 











40 



90 









507 



















509 



Pyrethrum 



1/3+2+100— 





















507 





















506 



"Cube" 























506 



1/4+2+100— 



"Cube" 























507 

























506 



1/5+2+100— 



"Cube" 























506 



1/6+2+100— 



"Cube" 























