- .75 - ^ 
Ceroplastes rub ens 1'ask., a pink v/ax scale 
Ishigai (133) in 1937 wrote of the use of derris in Japan, and 
argued that fresh' derris roots are nore effective than dried roots. Ground 
fresh roots plus soap as a spray ?;illed 80 percent of _C. r ub ens on per- 
simmon and from 80 to 100 percent of various coccidae on orange and pear. 
On the ether hand, farmers know that if the imported dried roots are used 
the results obtained are negligible. Something contained in the fresh 
crude root and lost in the dried roots appears to make the difference. 
This is an angle not yet studied by scholars, perhaps because of the bad 
smell of the fresh crude roots, 
Chicnaspis euonymi Comst., the euor.ymus scale 
Rotenone 'in oil was highly effective in controlling this species 
on greenhouse plants,— -Turner (271) in 19 32, 
Hamilton (136) in 19 38 reported that cube and derris powders (4 
percent rotoncnt; and 16 to 18 percent total extractives), applied as a 
spray at -the rate of 4 pounds per 100 gallons with the addition of 4 pounds 
of rosin*»residue emulsion, were satisfactory as a contact poison against 
young scales on euonymus trees, 
Haude (144) in March 1939 recommended cube or derris powder spray 
(4 pounds powder containing 4 percent of rotenone plus 4 pounds of rosin- 
residue emulsion per 100 gallons) for the control of young scales. 
Chionas_pis furfura (Fitch), the scurfy scale 
According to Hammer (138), in 1936 results of preliminary tests 
against C, furfura using powdered derris root and a proprietary mixture 
of rotenone and .pyrethr'.wi extracts were not promising and were not 
tested further in 1937, 
Chionaspis pini f oliae (Fitch), the pine needle scale 
Rotenone in oil emulsified in water with powdered milk (rotenone 
1:25,000, 1,0 percent oil) killed 100 percent of the half-grown females, 
as compared with 5 percent killed by check oil, — Turner ( 271 ) in 1932. 
C h r y s omph a 1 u s aonidum (L. ), the Florida red scale 
Rotenone in oil was highly effective, — Turner (2 71 ) in 1932. 
LaDue (179) in 1938 reported that in the early part of 1937 labora- 
tory experiments we re -made using methyl isobutyi ketone, methyl-n— amyl 
ketone, and 2, 2 T -dichlorethyl ether as intermediary solvents for the derris 
resinate and tank -mix spray oil. Bbeling found that the methyl -n-aayl 
ketone-derris-resinate solution increased the toxicity of the oil to 
(Aonidielia) Chrysomphalus aonidum (L.). 
