- 81 - 
for the derris resinate and ta -- ix oi'I. The derris resinate-meth r l« 
n-anyl-ketone-oil mixture has been besi .. the black scale i bhe results 
indicate an added toxicity of the oil to this insect, ft by 
the addition of methyl-n-aiayl ketone cr 2,2 ? ~dichlcrethyl ether to the 
derris por r der seemed to increase the e . the material. 
Ebeling (92) in 1940 reported bh cone-be •-: ; roots 
have been used in California for a numb< ■ incr f: c- 
tivencss of spray oil against the black scale. They hav ter 
possible a reduction of oil dosage from the u c i^ n 1.5-1,67 percent tc 1 
percent or less, 
C o c c i da e ( un i d e nt if i ed species ) 
Coccidao in general are not affected by derris. — ' ■ Laan ( 178 
in 1956. 
Van der Yecht (287) in 1933 reported that r_ ?rimc: ts v. r ith derris 
inst Ccccid'.e had so far failed to give satisfactory result's. 
,Uiil o 
From 80 to 100 percent of various Coccidae on oras - r.d pear - r r.r? 
killed by the application of ground fresh derris roo - 3 lus soap jas a 
spray. — Ishigai (163) in 1937, 
Mealybugs 
Corbett (52), entomologist for the Federated ?.'.al . s Depart- 
ment of Agriculture, reported in 1^30 that tv? used at the rat's of 1 
pound to 10 imperial gallons of Crater is a go< i: secticide for general 
use in the garden, as plant., regularly tprayed v. r ith it r.dll be kept com- 
paratively free from mealybugs. Laidenhair fern a'nd similar plants are 
often diTcrfed in ;-ro~.doh by mealybugs: a tuba spra 1 v/culd be found very 
V 
satisfactory in controlling them, 
Jones and Davidson ( 164 ) in 1931 report" t rotonone rris 
extracts prepared v/ith r ish oil have a high toxicity to mealybu . 
Davis (36) in 1932 rrrote that •if. penetr ting niscible oils derris 
has proved very effective inst mealy 
The Rubber Service Laboratories Company, a subsidiary oi the 
Monsanto Chemical Company (238) in 1935 reported that - ray cor gaining 
7 rts of derris resins, 33 parts iry Aresco, :o rt: ' e cil 
(or oleic acid) is effective against i lybi ;s it 1:200, The " or/in - 
mixture at 1:200 v/as found to he effective: Dorris-rcsin 7 parts by 
'vveight, dry Aroskap 52 parts, and cither pine oil cr oleic acid 60 ..arte. 
