, .. -43- 
Simenton said: -..',.. 
In one actual . embodiment of the invention I 
prepared such a solution, oy first forming a 5-percent 
solution of crystalline rotenone in &i ethylene 
glycol mcnethyl ethur acetate and then adding 1 
part 'of this solution to 100 parts of a petroleum 
naphtha extract of pyre thrum flowers prepared by 
extracting 1.2 pounds of pyr^ thrum flowers ^ r ith a 
deodorized petroleum naphtha. The resulting .product 
.'"as. a stable, nonvolatile, substantially odorless 
solution of excellent insecticidal properties. 
"When tested according to. the F.eet-Grady method, 
the solution repeatedly gave, a knock-down value 
of 98 and a kill of 85. 
Sullivan ( 256 ) in 1937 reported that an increase in con- 
centration of pyrethrins in semiconcentrate fly sprays of 
wyrethrum at first . brought a bout, a corresponding increase in 
toxicity to houseflies, . but at higher concentrations the mortality 
curve leveled off. When sarrrolesof pyrethrum of different 
pyrethrin concentration were diluted to the same concentration, 
the mortality of the flies was nearly the same in all cases. 
Semiconcentrate fly sprays containing paired combinations of 
rotenone, an aliphatic thiocyanate, and pyrethrins, when undiluted 
sieve almost equallv high mortalities in 3 days, but when diluted 
with 2 parts of kerosene there vss a vide range in kill. A com- 
parison of the mortalities at the end 1, 2, and 3 days showed the 
desirability of a 3-day observation period ^hen the spray contains 
rotenone. It seems, therefore, that the best method for the bio- 
logical testing of semiconcentrate fly sprays is to dilute them 
and compere them with a standard. Pyrethrins (0.3 percent) plus 
rotenone (0.1 percent) gave a higher kill then pyrethrins (0.3 per- 
cent) plus an aliphatic thiocyanate (2.5 percent) '-or than rotenone 
(0.1 percent) plus en aliphatic thiocyanate (7.5 percent}. The 
action of the pyrethrins and the aliphatic thiocyanate, '-hen used 
alone, was complete over a 24-hour period, producing death or a 
complete recovery of the flies, whereas rotenone is a slow— acting 
poison reouiring a 3-day observation period. *or this reason 
mortality counts were made at the. end of the first, second, and 
third days. • 
Roark ( 241 ) in 1938, in a review of the comparative insecti- 
cidal value of derris and cube of enual rotenone content, referred 
to the work of Jones and Smith ( 157 ) and of Camnbell, Sullivan, 
and Jones (53) , who tested extracts unon the housefly and reported 
derris to be superior to cube.. 
Sullivan, Phillips, and McGovran ( 268 ) in 1938 reported that 
an extract of the fruit" of the Amur cork tree (Phe llodendr on 
f murense) showed considerable toxicity when tested against the 
housefly, being about as toxic es derris containing 5.2 wereent of 
rotenone. 
