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Delassus and Laffond (92) in 1S36 reported the results of tests of 
derris against this species on grapes in Algeria. Powder A contained 1.5 
percent of rotenone and other derris constituents; powder 3, 2.0 percent 
of rotenone and related substances; powder C, 3 percent. Two applications 
were made on August 2 and 9, 1935, by hand dusters. On August 4 there was 
a flight of butterflies of the third generation. Dosages applied were 130 
to 160 kg. per hectare per treatment—an excessive amount. Almost com- 
plete protection was given by powders A and C; powder B was coarser and 
did not adhere so well. In 1937 these authors (93) concluded that 15 to 
30 kg. of derris dust containing 2 percent of ether extractives per hec- 
tare gave satisfactory results. Derris residue on the grapes was visible 
a month after application but did not interfere with fermentation or im- 
part a taste to the wine. 
An anonymous (6) writer for the Palestine Gazette in 1938 reported 
that during the preceding 2 years substitutes for arsenicals had been 
tested at the Entomological Laboratory of the Plant Protection Service, 
Acre Stock Farm and Agricultural Station, for the control of this species. 
Derris and pyrethrum proved effective in the laboratory but had always 
been a failure in the vineyard, owing to two facts: (l) The active prin- 
ciples, the rotenone and the pyrethrins, easily break down in the sun 
and heat of the climate of Palestine in 3 to 4 days. (2) It is practic- 
ally impossible to apply these dusts so punctually as to meet the larvae 
just at their emergence or very close to it. The so-called stabilized 
derris preparations have not proved better than the normal ones. 
Jancke and Maercks (219) in 1938 reported on laboratory experiments 
in Germany to determine the length of time during which sprays of nicotine 
and sprays or dusts of pyrethrum or derris remain active. The insecti- 
cides were applied at usual concentrations to glass dishes, and test in- 
sects were placed in them at known intervals after the application, left 
there for about an hour (uncovered, to preclude fumigant action), then re- 
moved to unpoisoned food in clean dishes. The mortality was ascertained 
after 2 days. Batches of varying numbers of larvae were similarly tested 
or sprayed directly. Y.hen they were sprayed directly, the mortality was 
estimated after 3 days and was similar (70-81 percent) for crude nicotine 
and soap, tobacco extract and soap, and preparations of pyrethrum, or py- 
rethrum and derris. TVhen tested by the first method, the tobacco extract 
was the most effective spray, giving 75 and 40 percent mortality of lar- 
vae placed in the dishes 2 and 24 hours after application. The pyrethrum 
and pyrethrum-derris sprays wore disappointing, the latter giving no mor- 
tality. Pyrethrum dust and pyrethrum-derris dust gave percentage mortali- 
ties of 100 and 79, respectively, when the interval was 2 hours. A derris 
dust gave 100-percent mortality when the intervals were 2 and 6 hours, and 
95 percent xvhen they were 24 and 48 hours. 
Paillot in 1940 ( 523 ) briefly summarised the results of experiments 
on control of the two vine moths ( CHysiana ) Pha Ionia ambjp;uella (libn. ) 
and Polychrosis botran a in several districts ii. France. Arsenical sprays 
were reported to be superior to dusts containing 1 percent of rotenone 
which, however, were more effective than dusts containing barium fluo- 
silicate. 
