-84- 
Ceramica picta (Harr.), the zebra caterpillar 
The United States tyenaHjme^t^L Agriculture, Bureau of Entomology and 
Plant Quarantine ( 437 ),/a~t 'the 1954 meeting of the American Association of 
Economic Entomologists Cory led a discussion of field results with arseni- 
cal substitutes for the control of vegetable insects. Huckett and Harvey 
of New York stated that the zebra caterpillar had been practically unaffec- 
ted by applications of derris, cube, or pyrethrum powder. These results 
were also published by Huckett and Hervey ( 204 ) in 1935. 
Hervey, Huckett, and Glasgow ( 189 ) in 1935 reported that this insect 
is very resistant to derris dust. 
Howard, in a typewritten report to the Division of Truck Crop and Gar- 
den Insect Investigations, of the Bureau^ in 1935 reported that derris root 
mixed with talc, infusorial earth, or tobacco dust so as to contain from 
0.5 to 0,75 percent of rotenone, and used at intervals of 7 to 10 days at 
dosages of 25 to 30 pounds per acre per application, was not very effective. 
Howard, Mason, and Davidson ( 197 ) in 1935 reported that derris dust was 
not very effective. 
"White ( 480 ) in 1935 stated that derris was ineffective. 
Huckett ( 202 ) in 1936 reported insectary tests with pyrethrum, derris, 
and nicotine against third instars. The derris contained 4.5 percent rote- 
none and 16 to 18 percent total extractives. The results were as follows: 
Mortality after 
Spray formula 96 hours 
Percent 
Derris powder 2.5 gm. , skim-milk powder 1P.2 
2.5 gm. , water 500 cc. 
Derris powder 2 gm. , skim-milk powder 8.7 
2.5 gm. , water 500 cc. 
^Derris powdor 1.25 gm., skim-milk powder 7.8 
2.5 gm. , water 500 cc. 
Check 3,6 
Powdered derris root (4.5 porcent rotcnono, 15 to 18 percont total 
extractives) at strengths comparablo to 4, 3, and 2 pounds of powder 
100 gallons of water, was ineffective against the zebra caterpillar. 
Huckett ( 203 ) in 1938 stated that, in recent developments in cabbage - 
control on long Island, the larvao of the zobra catorpill r rgely 
immune to derris powder butthat pyrethrum dust was effective. 
