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100,000 hectares in Europe had been dusted either from aeroplrnes or from 
the ground, the former method being used about twice as often as the lat- 
ter. The use of a ground duster presupposes that the ground is fairly 
even and also that the trees are planted in rows between which the A-ehicle 
can move. It is used when the areas are fairly small, not exceeding 100 
hectares. In Germany several preparations containing a mixture of pyreth- 
rum and rotenone were used during the last 2 years with great success. 
Peridroma margaritosa (Haw.), the variegated cutworm 
Washburn ( 472 ) in 1934 reported that derris was ineffective as a stom- 
ach poison to last instars of (l ycophotia ) Feridroma margarito sa. Kale 
leaves were dusted and made into sandwiches, so that there w ould be no 
contact between the dust and the bodies of the larvae. Thirty larvae were 
fed sandwiches of 10 percent ground derris dust (6 percent rotenone) in 
diatomaceous earth, with no ill effects whatever; 30 larvae were fed pure 
ground derris dust (6 percent rotenone) with no ill effects; 30 fourth 
instars were fed derris dust (6 percent rotenone) with no ill effects; 20 
fourth instars were put on leaves freshly dusted with pure derris dust and 
showed no ill effects. The only effect noted was that the derris seemed 
to be somewhat repellent, as the larvae did not eat so freely of the treated 
material as they did of the untreated. 
Plathypena scabra (F. ), the green clover worm 
Brannon (47) in 1937 reported that recent experiments at the Norfolk, 
Va., laboratory, designed to determine the relative effectiveness of der- 
ris, derris-sulfur, cube, cube-sulfur, pyrethrum-sulfur, and sulfur alone, 
applied as dusts or as sprays for the control of the Mexican bean beetle in 
association with the green clover worm infesting snap beans, showed that 
in general the dusts were more effective than sprays for the control of the 
latter insect on beans. The derris and cube-dust mixtures contained 0.5 
percent of rotenone, the derris and cube sprays contained 0.015 percent of 
rotenone, and the pyrethrum-sulfur dust mixture contained 0.1 percent of 
total pyrethrins. lettable sulfur was used as a spray at the rate of 2 
pounds to 50 gallons of water. It was also noted that sulfur dust alone 
gave foliage protection against the green clover worm comparable with that 
obtained when sulfur was used in combination with derris, cube, or pyre th- 
rum, and that a derris-sulfur dust gave better protection than a derris- 
talc mixture. These results indicate that sulfur acts as a repellent 
against this species and that in instances where this pest occurs in assoc- 
iation with a Mexican bean beetle infestation, sulfur should be used as a 
diluent for derris or cube for the combined control of the two insects. 
Haude in 1939 stated in advertising literature published by the John 
Powell Co., New York, N. Y. that rotenone dusts may be used to control 
green clover worms where it is desired to avoid poisonous residues. 
Polia oleracea (L.) 
Lloyd ( 256 ) in 1920 reported tests of preparations made by Tattersfield 
of tuba root (derris) against larvae of the glasshouse tomato moth, (l) as 
a dry dust alone and in dilution with powdered earth; (2) with saponin in 
water suspensions at various strengths from 0.25 percent to 10 percent by 
