TOXICITY OF ORGANIC INSECTICIDES TO CODLING MOTH 9 
Attention is called to the fact that the foregoing results apply only 
to the toxicity of the compounds shortly after their application as 
sprays. According to these data phenothioxin and thiocoumarin are 
apparently promising insecticides for the codling moth. The writers 
wish to point out in this connection, however, that residual tests, in 
which the apple plugs (kept under laboratory conditions) were infested 
several days after the application of these compounds, indicated a 
considerable loss in effectiveness. Perhaps these losses could be over- 
come if the compounds were applied to the fruit under conditions 
different from those used in the experiments. 
The attention of the reader is also called to the fact that certain 
compounds have admitted a relatively small percentage of worms, 
but at the same time have allowed a high percentage of stung fruit. 
2-Phenyl-benzoxazole, for example, has given 8 percent of wormy and 
52 percent of stung iruit. Since conditions in the field are generally 
more unfavorable to the spray material than are conditions in the 
laboratory, the possible value of a given compound should not be based 
solely on the percentage of wormy plugs as obtained in laboratory 
tests. Stings made under laboratory conditions may be potential 
entrances in the field. 
