-160— 
Gimlette ( 162 ) in 1923 referred to tests by Durham who, in 1903, found 
that caterpillars were easily poisoned by derris. 
Lewin ( 250 ) in 1923 wrote that in Sumatra diluted derris-root sap v.us 
used to kill caterpillars on young tobacco plants, but too great a quantity 
killed the tobacco, 
Tattersfield and Roach ( 403 ) in 1923 referred to work carried out be- 
tween 1902 and 1907, by Durham, who reported that larvae of Lepidoptera 
were very susceptible to derris. 
The preparation of derris for use as an insecticide was* described by 
the Federated Malay States Department of Agriculture ( l2l ) in 1924, as 
follows: 
For small caterpillars and sucking insects, where a simple wash 
is required, the derris spray can be made on the spot. I T se the fol- 
lowing proportions: Derris root 4 to 5 pounds, soap 2 pounds, water 
50 imperial gallons. 
Cut the derris root into snail pieces and pound to a pulp in a 
mortar with a little water. Inclose the pulp in a cloth and squeeze 
well in a larger quantity of water. To the extract obtained by this 
process add the soap, which has been dissolved in a little hot water. 
Then dilute to 50 gallons. 
Alcoholic extracts of cube and derris plus soap were ineffective 
against first-instar webworms, as was also derris used as a fumigant. — 
Mclndoo and Sievers ( 265 ) in 1924. 
Caterpillars can be easily exterminated by the application of insecti- 
cides containing derris or its products. — Carlos (_G5) in 1926. 
Tattersfield, Giinihgham, and Morris ( 402 ) in 1926 reported • re- 
liminary experiments indicated that the haiaris ar. roria v id 
T. toxicaria , as stomach poisons are both repellent and toxic to e 
pillars. 
The application of a commercial derris spr tiled cabbage 
within a half-hour. Cabbage butterflies flew away. — Anonymous (l) 
1927. 
The Institute of Physical and Chemical Research ( 214 ) Tokyo, Ji 
in 1927 reported that Neoton gave 100-percent mortality oV caterpJ 
green caterpillar at the rates of l/2 poun ] pound of Moot, 
imperial gallons of water. 
Leefmans f 248 ) in 1927 reported that on the 
growers are mixing load arsenate with the usual • ion. 
suspension in water gave . ^ablc results a i I I 
but excellent results were obtained when finely 
tracted with alcohol. The i Lon of a water derris or d - 
ris roots to a solution of lead arsenate seemed I , beoauee T I 
with the addition of soap, was satisfactory. 
