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Aphi s njjnicis L. in an insectary experiment was killed completely 
"but slo'/ly "by derris, 5 pounds to 100 gallons. Derris spray 2-112 pounds 
to 100 gallons gave a mortality of over 90 percent of imported cablDage worms 
Pieri.s rapae L. , on cablDage. Busts of hydrated lime and derris were not 
so effective. The authors concluded that the moisture usually retained "oy 
ca"b"bage foliage undouhtedly assisted in "bringing out the toxic properties 
of derris. 
Undiluted derris dust, applied with a hand duster, gave 100 percent 
control of larch sawfly larvae. Derris dust had apparently no effect on 
Chermos . The three-lined potato beetle was controlled "by a dust application 
of 50-50 derris and hydrated lime, "but this mixture had apparently no ef- 
fect on the squash bug. A red aphid on goldenrod and the currant a,phid 
wore not controlled on being dusted by the same mixture, but reasoning 
from other experiments it is possible that they might have been if in the 
presence of moisture. 
Derris, both dust and spray, gave a measure of control against the 
larch case bearer. 
Derris, both dust and spray, v;as ineffective against the chain- 
dotted geometer, but arsenicals v/ere practically ineffective against them 
also. 
Derris, I-I/2 pounds per 100 gallons of water, v/ith the addition of 
soap, was used against aphids on a cut-leaf birch. G-eometrid larvae, lady- 
bird beetle larvae, and syrphid fly larvae v;ere killed and dropped in a 
fev/ hours, but the aphids did not appear to be affected during the first 
12 hours. Tv;o days later the tree v/as found to be completely free of 
aphids. 
Derris was not effective in a bait fed to cutworms, either in the 
insectary or in the field. 
It v/as noted in some cases that v;here dusts containing derris had 
been supplied to plants, and later rains had washed the dust into the soil, 
the earthworms came to the surfact of the soil and died. 
Derris, applied at approximately the rate of 1 pound per 100 gal- 
lons, added to a large tanlc of v/ater very heavily infested with mosquito 
larvae, completely killed all the lai'vao in 3 or 4 days. 
It was also noted that if slugs traveled over a surface on xAiich 
derris had been lightly sprinkled, the slugs immediately became distressed 
and died in a few hours. 
Derris, used undiluted and also at the rate of 1 part of derris to 
3 parts of dry cement pov;der, was found very effective against lice on 
cattle and horses. 
IlcBride (64) in 1926 reported tests with insecticides against a leaf- 
hopper, Eupteryx flavoscxita var. nigra . Osb. , attacking the leather-leaf 
fern, Polystichum capcnsc J. Sm. , in Florida. 
