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Derris or cube dusts have given unsatisfactory results in tests 
for the control of the cabbage aphid. — Walker and Anderson ( 298 ) . in 
August 1939. /-.. . 
Howard ( 152 ) in lQUo reported that' a nicotine-dust mixture was 
superior for cabbage aphid control to the rotenone-tobacco-sulfur mixture 
recommended for turnip aphid control in the South (cf. report on Rhopalo - 
siohum pseudobrassdcae , .p. U7). 
The Wisconsin Agricultural Experiment Station C 32I ) in 19U0 re- 
■00 r ted that a mixture of derris 25 pounds, hydra.ted lime 37. 5 pounds, 
dusting sulfur 37-5 pounds, and nicotine (Black Leaf ^0) 5 pounds gave 
good control of both cabbage worms and cabbage . aphids. The sulfur kept 
the derris effective against cabbage "orms, even though the reaction of 
the mixture was sufficiently alkaline to release the nicotine necessary 
for aphid control. 
Capitophorus fragariae (Theo.), the strawberry aphid of England 
Rogers, King, and Mas-see ( 23b ) : in 1935 reported that, for the con- 
trol of _C. fragariae in England, derris sprays and dusts, nicotine dust, 
nnd pyre thrum spray have been tried extensively but do not give sufficient 
control to warrant their use commercially. 
Capitophorus rib is (L.), the currant aphid : 
The currant aphid was not controlled by a dust of enual parts of 
derris and hydrated lime, according to iCelsall et al. ( 169 ) in 1926. Al- 
though derris and soap is highly toxic to : ar>hida and similar soft-bodied 
sucking insects, a dry powder appears to be less efficacious. Thus a 
derris dust failed to control a bad attack of _C_. ribis on red currants 
in a garden in June 1935, but when a wet spray was used satisfactory 
results were obtained. 
Capitophorus rosarum ( Kal t . ) • ■ ; 
The pondered roots of four snecies of derris applied as dusts 
killed from 63 to 92 percent of these aphid? on roses in U days. — DeOng 
(75) in 1930. 
Foliafume (a pyre thrum— derris spray with spreader) at 1:U00 killed 
91 percent in Ug hours. — Penick and Company ( 223 ) in 1936. 
Cavariella sp. 
Brittain (21) in 1925 reported that field tests to control Cavari - 
ella so. on ; parsnips, were made v > r ith derris (2-1/2 pounds of derris and h 
pounds of soap powder aer 100 imperial gallons of water) and a commercial 
preparation of derris, Polvo (2-1/2 pounds per 100 imperial gallons). 
Each reduced the infestation very little, even when soap was added. In 
the insectary infested leaves were dialed directly into different insecti- 
cides. Derris, 3 pounds per 100 imperial gallons, killed only 10. U per- 
cent; derris, 2-1/2 pounds per 100 imperial gallons plus h pounds McDoug- 
a'll's soap powder, killed 91 percent. 
