-50- 
Rotenone dusts killed some sciarid flies but seemed to be much slower 
in action than pyrethrum dusts, and heavy dosages of proprietary 
rotenone compound c placed in the manure were ineffective against 
insects there, perhaps because these compounds were affected by the 
alkalinity of the manure. 
Miles and Miles ( 203 ) in 1935, in discussing the use of derris- 
for combating greenhouse pests, said that soil or manure infested 
irf ith eggs or maggots of fungus gnats, Sciara sp., should be treated /bei: 
with some insecticide such as derris or pyrethrum before/taken into 
the house. 
The United States Department of Agriculture, Bureau of Entomology 
and Plant Quarantine ( 291 ) in 1938 stated that tests made against 
various species of mushroom ■ flies, Sciara sp., in the "mushroom houses 
at Beltsville, Md., with a number of drenches and with derris powder 
demonstrated that the drenches containing free nicotine or the alco- 
holic extract of pyrethrum gave the best results as judged by crop 
yield. 
Hamilton ( 132 ) in 1939 recommended derris or cube extract sr>rays 
as contact poisons for the control of white maggots in the soil 
around house plants. 
-Oestridae 
Hyp ode ma bo vis (Deg.), the northern cattle grub 
See Bishopp et al. (29,32) Case (58), MacDougall (188), Be Bussy 
et al. (48), Wells and Schroeder ( 3137 7 the United. States Department 
of Agriculture, Bureau of Animal Industry ( 281 ) , Bureau of Entomology 
and Plant Quarantine ( 297 ) , and Wells ( 311 ) under Hypoderma lineatum 
(De Vill.)/ 
H ypoderma crossi Patton, a goat warble fly 
See Bhatia (26) under Hyp Oder na. lineatum (De Vill.), on page 51- 
Hypoderma lineatum (De Vill.), the common cattle grub 
Bishopp et al. (29) in 1926 reported that a proprietary derris 
extract, 1 part, plus 10 parts of water (containing 4 oz. of soap 
per. gal.), killed 100 percent of cattle grubs when injected with an 
oil can directly into the grub holes in the backs of the cattle. 
Derris powder, 8 ounces, plus soap, 4 ounces, per gallon of 'vater, 
applied twice as a wash on the back,, also killed 100 percent of the 
grubs. Tests with dry derris powder, derris powder with paraffin 
oil, derris powder with petrolatum, derris rodder "uth soap and 
water, and derris ponder rT ith 'vater only are recorded . The percentage 
mortality of Hypoderma. bovis Deg. -7as not so high as that of H, 
l ineatum . The authors concluded that tests of the an-olic-' tion of 
'"ashes, powders, and ointments to the backs of the cattle and also 
