- 77 - 
re' 
Dusts carrying 0.2 percent of pyrethrins or 0.75 percent of rotenone, wfc 
is higher than called for in cost recommendations and also higher than t 
contents of most commercial dusts, failed to give satisfactory control. 
This station in 1937 (76) reported that seasonal tests failed to give a 
isfactory control of c*bbaee loopers. 
Fenton ( 129 ) in 1936 compiled information on mixtures of sulfur wit 
derris used for the control of this species. 
Gui ( 171 ), of the Ohio Agricultural Experiment Station, in 1936 re- 
ported that in 1934- a spr- y of 1 part of Rotecide plus 1 part of New Eve 
green to 800 parts of water controlled 71.1 percent of the cabbage loope 
A. derris-clay dust (0.5 percent rotenone) gave 74-»6 percent control. In 
1938 Gui ( 172 ) reported that for the protection of cabbage against cabbai 
worms, including this species, the crop should be dusted or sprayed at li 
intervals with paris green or derris powder. Derris-powder dusts should 
contain not less than 0.5 percent of rotenone, and 1 pound of derris pow 
(4- percent rotenone) should be used to 7 pounds of the diluent. Desirab 
diluents for derris powder are flour, talc, diatomaceous clay, dusting 
gypsum, and finely ground tobacco fetems. Derris-powder spr ys should 
consist of 1.5 pounds of derris powder (4- percent rotenone) in 50 gallon 
of water, ^'hen other grades of derris powder are used, dosage should be 
so calculated that the spray contains 0.015 percent of rotenone.. 'A' spre 
er" a nd sticker should be used. Feder - ! regulations prohibit excessive 
residues of poison on marketed cabbrgej therefore paris green should* not 
be ap lied after the heads begin to form. Derris po*"dei~ may be used, aft 
that date or throughout the season if desired. There are no regualtions 
at present concerning residues o^ rotenone on fruits and vegetables. 
The New Jersey Agricultural Experiment Station ( 293 ) in 1937 reports 
that derris dusts gave' satisfactory results against cabbage worms, inclul 
ing this species. 
Shropshire and Kadow (369) in 1936 recommended derris and cube for I 
control of the cabbage looper. These materials are most -effective when I 
applied as a dust lata in the afternoon. The dust should contain at 
least 0.5 percent of rotenone and should be applie- 1 at the rate of 20 to/ 
pounds per acre, ." ' before the worms become abundant, applicat 
•being repeated at intervals of 10 days to 2 weeks or as often as necessar 
Unlike metallic poisons, derris products a^e sqfe to use on crucifers up ■ 
' to the time of cutting. Derris sprays c-n be used for the control of 
cabbage worms, if applied according to the manufacturers' directions. 
The Texas Agricultural Experiment Station ( 4Q4- ) in 1936 reported tha 
derris was more effective than, cube against the cabbage looper, regardles 
of the carrier used, accord ing to tests conducted at '"'eslaco and "interhaj 
in 1935. The derris mixtures and tre cube mixtures '-aere more effective 
against the larvae of the diamondback moth than against the cabbage loope 
Derris-sulfur (1^:85) or cube-sulfur (15*85) containing 0.75 percent of 
rotenone gave better control of cabbage worms on the average than either 
le-id arsenate or barium fluo'silicata, in the lower Rio Grande Valley, the 
'.'inter Garden, or Galveston County. This station in 1937 reported that 
results in two series of experiments indicated very little difference betii 
sulfur and fuller's earth '-hen tl ey were mixed with cube for the control 
of the cabb?ge looper. 
