-10- 
percent of the beef medium on which they fed. 
Lucilia cuprina (Wied.) 
Lennox ( 178 ) in 1940 wrote on the ection of stomach larvi- 
cides on "this spe«ies. The toxicity of a* number of compounds 
was measured by (A) growth retardation and (B) rate of action. 
Derris extract was toxic et concentrations of 0.1 and 0.01 per- 
cent, 
Luoilia sericata (Meig.) 
Laake et al. ( 165 ) in 1931 reported the results of tests 
of materials as attrectants or repellents to this greenbottle 
fly. Beef-liver bait 4 ounces, to which 5 gin. of derris "oowder 
was added, attracted only 40 percent as many as did untreated 
bait. A mixture of 1 part of derris powder and 9 parts of 
kaolin attracted 20 percent. 
Baudet and Nieschulz (23) in 1933 reported that derris 
powder containing 2 percent of rotenone ^as entirely inert 
toward the larvae. Four-day-old larvae cradled around in the 
•derris nowder for 3 hours without suffering any ill effects. 
A suspension of derris powder in soap and water was also "nth- 
out effect on the mobility of larvae submitted to the influence 
of this suspension for a 5-minute period. Pine oil "as found 
to be toxic to the larvae. The addition of rotenone to oine oil 
in quantities of 0.1 to 10 percent did not increase the toxicity 
of the pine oil. It was concluded that derris ponder and rote- 
none are inactive toward the larvae. 
According to Van der Laan ( 166 ) in 1936, this species is 
not affected by derris. 
Hoskins et al. ( 143 ) in 1940 reported that rotenone mixed 
with a synthetic diet in which larvae of this species "*ere 
placed was toxic at the following concentrations: 
Concentration ♦ Mortality ■'• Stage of Insect 
Second and third 
instars. 
Second and third 
instars; pupae. 
Second, third and 
fourth instars. 
L ucilia sp. 
Parman et al. ( 2°6 ) in 1928 reported that derris ponder 0.5 
gm. plus' kaolin 4.5 gm., spread upon 4— ounce cubes of beef liver 
in a meson jar, repelled 81 percent of the flies that ap'rorched 
Percent 
1/12 8 percent 
ICO 
1/256 percent 
98 
1/512 percent 
62 
