-39- 
J. nes end Smith ( 157} in 1936 proposed formulas for cal- 
culating from the rotenone end total extractive contents the 
approximate toxic value to houseflies of samples of derris and 
cube roots. .The toxic value of derris root eouals rotenone 
content plus 0.5 of the rotenoid content; that of cube root 
is the seme except that a factor of 0.4 instead of 0.5 is used. 
The rotenoid content is. the total-extractive content obtained 
with carbon tetrachloride, benzene, or acetone, minus the 
rotenone content. 
Bedertscher (11) in 1936 compared results by the Peet-Gredy 
method end the Campbell turnteble method. One sample tested con- 
sisted of 90 percent of Deobase and 10 percent of oil of sessefres 
and carried 1 gm. of rotenone per liter. Results by the two 
methods (50 tests each) on this sample were as follows: 
Method 
Flies used 
• PI 
ies down 
in 
Flies deed in 
; Jl 
ies dead 
•• 10 
minutes 
24 hours 
in 
48 hours 
Number 
Percent 
Percent 
Percent 
Peet- Grady 
4,785 
94 
1 64- 
91 
Campbell 
4,859 
88 
59 
89 
• Badertscher concluded that the Peet-Gredy method yielded higher 
kills on pyre thrum sprays and thi'ocyenate sprays than did the 
Campbell turntable method, but the turntable method yielded higher 
kills on sprays that conteined rotenone then it did with straight 
pyre thrum sprays. 
DeBussy et al. (48) in 1936 reported that the housefly was 
controlled by dusting with derris (rotenone 7 percent, but sprays 
of derris mixtures containing 0.5 and 1.0 percent of rotenone killed 
only about half the flies and many ''ere only temporarily incapacitated 
Cory, Herns, end Anderson (63) in 1936 reported that pyre thrum 
and derris dusts had little or no repellent action against the 
housefly under conditions of forceful tropism. The housefly was 
less susceptible to the toxic action of pyre thrum and derris dusts 
than was the steblefly. 
According to Van der Laan ( 166 ) in 1936, the housefly is some- 
what sensitive to derris. 
LePelley end Sullivan ( 179 ) in 1936 reported a studv of the 
toxicity of rotenone and pyrethrins, alone and in combination, to 
houseflies, when tested by the turnteble method. Rotenone was from 
u\ 
aBRARV 
STATE PtAN T #**?• 
