-41- 
were not effective against last ins tars. Dosage was regulated to give a 
deposit of 0.18 mg. of rotenone per 500 en. . 
Hymphalidae (unidentified sp. ) 
Sprays made by extracting Tephrosia vogelii seeds with kerosene 
proved about half as toxic to unidentified caterpillars of this family 
as similar sprays containing pyrethrum. — Worsley (499 ) in 1934. 
Oecophoridae 
C remona cotoneasteri Busck 
Roaf, Dimick, and Mote ( 556 ) in 1937 reported tests against this 
webworm on Cotoneaster horizontal is near Portland, Oreg. A derris dust 
applied to the infested shrub with a large salt shaker gave good control. 
This dust v/as prepared by mixing 1 part of derris (rotenone 5 percent) 
with 9 parts of hydrate of lime. This mixture did not kill the cater- 
pillars quickly but in a week's time most of the webworms were dead. 
After the caterpillars died a garden hose was used to wash the material 
from the plant. 
Depressari a nervosa Haw. 
The Wageningen ( 461 ) Station in Holland in 1934 reported that spraj^s 
containing 0.01 percent of rotenone, 0.25 percent of acetone, and C.2 per- 
cent of Agral gave from poor to fair control. 
Blijdorp (36) in 1935 reported that derris powder containing 2 per- 
cent of rotenone v/as the best of several materials tried for the control 
of the caraway moth. This was applied at a rate of 37.5 and 75 kg. per 
hectare (equivalent to about 33.5 to 67 pounds per acre), in two applica- 
tions using one-third of the total amount in the first application. The 
results were obtained by measuring the yield cf caraway seed obtained 
from each of four experimental plots 10 by 20 meters, and counting the 
number of cocoons. Lr tor Dlijdorp (37) reported that for control of 
this moth it is almost always betterTo apply an insecticide as a dust 
than as a spray, advocating derris of known rotenone content diluted with 
talc. Dusting is worth while if a count at the end of March over a few 
square yards indicates the presence of more than 6 to 8 thousand females 
per acre. 
Spoon ( 584 ) in 1935 reported on the control with derris powder in 
Holland. Derris powder (8 percent rotenone, 21 percent other extract) was 
mixed with 3 ^arts of French chalk. This mixture at 53 pounds per acre 
gave better results than 133 pounds per acre of either 20 percent of bar- 
ium fluosili >.ate or 50 percent of sodium fluosilicate. At 66 pounds | 
acre this derris mixture gave practically complete control. 
