-22-- 
such products^ — an insecticidal effect ras obtained which was far great 
er than the effects exerted by the two drugs used singly. This is 
shown by the ToIIdwing comparative tests made by using strewable prep- 
arations consisting' of intimate' ground "mixture's of sabadilla seed 
with talc, Derris elliptica root with talc, and with a mixture of saba 
dilla seed and D_. elliptica root. In each test 30 caterpillars of 
Tephroclystia absinthiaeta (CI.), placed on blotting paper, were duste 
with a quantity of one of the mixtures corresponding to 0.16 mg, per 
square centimeter, the powder being evenly distributed. 
■ I ■!■»—! ■ I ' ■■ ■ WWII— WMP— ^1*»W^»—W I li<|l f ■! ■ i' II ■■ ■ - — — ■■■^ — — ■■ . 
• ' Caterpillars 
Preparation ' Killed * Not Killed 
Number Number 
Talc + 2.5 percent derris root 1 29 
Talc + 5 percent derris root 10 20 
Talc + 7.5 percent derris root 18 12 
Talc + 7.5 percent sabadilla seed 17 13 
Talc + 10 percent sabadilla seed 19 11 
Talc + 15 percent sabadilla seed 26 U 
Talc +2.5 percent derris root + 
7. c percent sabadilla seed 30 
Control test 30 
Geometridae (unidentified sp.) 
Geometrid larvae on a cut-leaf birch were killed and dropped 
in a few hours when sprayed with derris 1.5 pounds per 100 imperial 
gallons of water, plus soap. — Kelsall et al. ( 233 ) in 1926. 
The Institute of Physical and Chemical Research ( 214 ) Tokyo, 
Japan, in 1927 reported that the external or contact action of Neoton 
is effective against geometers (larvae). 
Turner (^18) in 1932 reported that in a field test some small 
apple trees received 2 sprays containing cube extract at the rate of 
1:25,000 and 1:12,500, to kill a heavy infestation of cankerworms. 
The sprays did not kill the worms, but no further feeding occurred on 
the sprayed trees. The larvae remained on the sprayed leaves for 
several days and were apparently normal in reaction to prodding. 
Hamilton ( 179 ) in 1935 stated that .powdered derris is more stable 
and cheaper ths>n derris extract. One pound of derris dust (rotenone 
1 percent) to 15 gallons of w^ter was effective against half-grown 
cankorworms. 
Van Gundia ( 452 ) in 1936 reported control of cankerworm on many 
varieties of shade trees with a rotenone dast containing approximately 
