-33- 
against young caterpillars of this species damaging padi. 
Lymantria aonacha (L.) 
See Tragardh (416) under Panolis c-ri scorer ieg^ta, on page 92 . 
Schwerdfeger (366) in 1932 reoorted experiments on the control of 
the nun moth with several proprietary insecticides, including an emul- 
sion (Derrothan) and two powders (Derrothan I and Derrothan II) contain- 
ing derris or extracts thereof. The powders, tested at 50 kg. per hec- 
tare, caused 100-percent mortality in 24 hours, and the emulsion also 
.was very effect ive 
Trappmann and Nitsche (417) in 1935 reported that rotenone sprays 
were not effective against last instars of this species . Dosage was 
regulated to give a deposit of 0,18 mg. of rotenone per 500 cm.^, 
Klinger ( 237 ) in 1936 reported that rotenone spray and dust gave no 
mortality in 8 days. These tests were made in the laboratory on fourth 
instars. 
Schotte and Gornitz ( 365 ) in United States potent 2,136,868, issued 
November 15, 1938, claim as an insecticide a finely divided mixture, 
solidified from the molten state, of an insecticidal vegetable materirl 
and a carrier substance, the said carrier substance being solid at 
ordinary temporatures, but molting below carbonization temperatures of 
said vegetable material and in its molten state being capable of ex- 
tracting the active insecticide from said insecticidal vegetable material. 
For example, derris root is mixed witn molten naphthol in the proportion 
of 3:5 and the solid mixture is ground with a suitable diluting agent, 
such as talc. ' The product is highly efficient against caterpillars and 
also possesses fungicidal properties o Comparative tests each mrde with 
50 5th •'instars, 44 pounds being; distributed on 2,5 acres, gave the follow- 
ing results: 
i j 
Test No. Killed after — ' Feeding 
i 7 days | 8 days Conditions 
1 , 1 1 
Number Numb or 
A. Mixture of inert powder 80 percent and dorris root 20 percent. 
1 20 30 Strong 
2 22 33 Strong 
3 15 30 Strang 
B. Mixture of inert powder, 80 percent and derris root-naphthol mixture, 
20 percent. 
4 32 39 Weak 
5 33 41 Not f 
6 29 35 ak . 
