Tho Foderatod Malay,, States Department of Agriculture (28) in 
1920 reported that in Perak, during Octooer and November, experiments 
were conducted on the control of Bona Kura, Podops coarctata P., a 
medium-sized brovm bug; stem borers, Schoenobius bipunctifcrus Wolk. 
and other species; and the mole cricket, G-ryllotalpa sp. Spraying 
with kerosene cmu.lsion and extract of tuba root ( Der"ris sp.) were tried. 
The results v/ere uncertain, 
1921 
Symcs (88) in 1921 reported that pure dcrris powder applied to a 
bed of mushrooms infested v/ith the mushroom fly, Sciara praccox Meig. , 
cleared the bed of insects in 2 or 3 days, but had no effect upon 
Hypomyccs fungi. It is concluded that nushrooms will not stand treatment 
with powder insecticides (such as pyrothnxrc, derris, and 1-pcrcent 
paradichlorobcnzene) . V/hcn not checked in their growth by these pov/ders, 
the mushrooms are rendered abs-alutely unfit for market. 
Parrott, Glasgow, and MacLeod (76) in 1921 reported tests v;ith a 
number of materials against two species of plant bugs, namely, the 
bright red bug, Lygidea mendax Reuter, and the dark red bug, Heterocordylus 
malinus Reuter. A derris-soap compound was used, a commercial preparation 
[Derrisol?] assiomed to contain approximately one-half pound of powdered 
derris root and 6 pounds of soa.p per United States gallon. This derris- 
soap mixture v/as used at the rate of 10 pounds to 100 gallons of water. 
Applied at the rate of 13-l/3 gallons per tree, the derris-soap mixture 
killed 99.2 percent of the insects. This same mixture, in three differ- 
ent tests, injured 5, 6.5, and 14.1 percent of the apples, the average 
being 13.2 percent. 
Smith and t/adsworth (86) in 1921 tested insecticides upon carrot 
and onion flies. Pour applications of a'powder composed of soot and 
derris at the rate of 1 ounce derris plus 2 ounces soot per square yard 
resulted in 95 percent clean carrots. The control plot yielded only 
20 percent carrots free from infestation by the carrot fly, Psila rosae P. 
This derris mixture gave the best control of any of the materials tried. 
Used against the onion flies, Hylemya ant i qua Meig., in the same way, 
six applications of derris-soot mixture (2 parts soot and 1 part derris) 
at the rate of 1 ounce per square yard gave 60 percent clean onions, 
v;hereas soot alone gave only 16 percerit clean onions. 
Howard (98) in 1921 reported briefly that a study had been made 
of the insecticidal constituents of plants, and 180 different prepara- 
tions had been made from 46 different kinds of plants, excluding tobacco, 
quassia, and derris, the properties of these being generally acknowledged. 
Of the 180 preparations, only a fev; were worth further study. 
Brittain ( ll) in 1921 described experiments in v;hich a 50-50 
mixture of derris v;ith clay and derris solution at two strengths (1-1/2 
and 3 pounds to 100 imperial gallons) v/ore applied to cabbage plants for 
the control of the cabbage m.aggot , Chortophila brassicae Bouche. The 
clay-derris mixture was applied at the rate of 960 pounds per acre. 
The derris solutions were applied at the rate of 10 and 20 pounds of 
derris with 650 imperial gallons of v/atcr per acre. All the derris 
