-31- 
Muscidae 
S iphon? irritens (L.), the hornfly 
The Louisiana Agricultural Experiment Station ( 183 ) in 1925 
reported that Derrisinc in a fish-oil-soap emulsion of red-pine oil! 
was effective in controlling or repelling hornflies on cattle. 
E. W. Laeke, of the Dallas, Tex.., If- Moratory of the Bureau of 
Entomology end Plant Quarantine, United States Department of Agri- 
culture, in e typewritten report to the Division of Insects Affecting 
Man and animals in 1936, reported that p ordered cube root, rotenone 
concentrate, and man'- other materials ^ere ineffective as repellents. 
Bruce (43,44) in 1940 reported results of tests on the medication 
of cattle for the control of larvae in the droppings. The general 
idee was to feed the cattle certain chemicals, which would pass out 
in the droppings and render them toxic to the lervae. The most 
effective meterial tested was rotenone. Doeses of C.4 gm. per 
hundredweight killed all larvae in the dropoings for approximately 
30 hours. 
Musca domestica L., the housefly _ 
See Doty (76_) under Stomoxys ca lci tra ns (L.) on page 49 . 
Mclndoo, Sievers, and Abbott (193) in 1919 reported the results 
of tests of derris powder; In cage tests, where flies were dusted 
in ordinary flytraps about 10 inches high, all were dead or inactive 
"ithin 24 hours. In room tests, where the powder was freely blown 
into the air and all parts of the room with a small hand dust gun, 
all the flies "ere dead at the end of 16 hours. In one test several 
hundred flies "ere liberated in a room that had "been thoroughly dusted 
days before. Very fe 1 " active flies were to "be seen 24 hours later 
and on the second day only 3 or 4 "were living. 
Kelsall et el. ( 159 ) in 1926. reported the results of tests in 
which derris at the rate of 5 pounds per 100 imperial gallons of 
rater was sprayed on the flies. The sprey was shot at them "both 
while they were resting and while thev were on the ring. Such flies 
became restless almost immediately and began cleaning themselves 
vigorously. M st flies ^ere dead within 24 hours esd all appeared 
to be dead within 48 hours. Derris was also dusted on flies but its 
action "es much slower and after 1 day none were dead, so" it was not 
considered effective. Had these flies been kept under observation 
longer, a subsequent mortality might hrvc been noted. Derris spray 
was also observed to kill several other flies of undetermined species. 
Fulmer (90) in 1930 reported that houseflies '•'ere emenable to 
derris. 
