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For control of the onion thrips in 1938 on carnations in green- 
houses, derris or pyrethrum extract with spreaders, ground derris 
with karaya gum and a wetting agent, nicotine sulfate with molasses, 
and tartar emetic with spreaders were all more effective than tartar 
emetic or paris green with brown sugar. In 1940 rotenone and pyre- 
thrum extracts combined with wetting and spreading agents failed to 
function as residual sprays against this thrips on carnations. The 
fact that they did not persist as toxic residues largely explained 
the failure. — Eichmann (161 , 162 ). 
ORTHOPTERA 
Blattidae 
Blattella germanica (L»), the German cockroach 
Pure derris dust was apparently as effective as pure pyrethrum 
dust against the adults, but neither was as toxic as sodium fluoride, 
— Dewey ( 141 ) • 
Mixtures containing cube and derris powders were inferior to 
pyrethrum mixtures. Results with cube were variable and indicated 
a low toxicity. A derris mixture (l percent of rotenone) gave 96 
and 72 percent kill of males and females, respectively, while another 
mixture (0.5 percent of rotenone) gave 88 and 56 percent kills.— 
Gould (239, p. 92). 
In a physiological study of the initial characteristic effects of 
insecticides upon the German oookroach, pyrethrum increased the rate 
of running while nicotine and rotenone (Derex) caused no acceleration. 
— Hut z el (304). 
In runway tests the percentages dead after 7 days were 100 for 
sodium fluoride, 13 for pyrethrum, 83 for sodium fluosilicate, 67 for 
rotenone, and 83 for borax. The average numbers of hours in which 
death occurred were 32, 101, 71, 73, and 83, respectively. The per- 
centages of cockroaches killed in 7 days after having been dusted were 
100 for sodium fluoride, 89 for pyrethrum, 60 for sodium fluosilicate, 
and 70 for rotenone, and the hours to kill averaged 9, 29, 87, and 96, 
respectively.— Laudini and Sweetman (359 ) • 
Rotenone did not cause marked mortality of female cockroaches and 
did not cause them to drop their oothecae.— Parker and Campbell ( 455 ) • 
Perlplaneta amerlcwna (L.), the American cockroach 
In runway tests the percentages dead after 7 days were 79 for 
sodium fluoride, 45 for pyrethrum, 8 for sodium fluosilicate, 38 for 
