4 MISSOURI AGRICULTURAL EXPERIMENT STATION BULLETIN 176 



presence of lice should not be disposed of until properly treated. Such trees 

 may be fumigated with hydrocyanic acid gas as recommended for San Jose scale 

 or the roots dipped in a solution containing one part of 40 per cent nicotine 

 sulphate to 500 parts of water. One and two-year apples are less likely to be 

 infested than older trees. 



In the orchard make sure that the young trees when planted are free from 

 lice. Use land that is not newly cleared but which has been cultivated for 

 several years. If possible do not have old worthless apple trees, haws and 

 elms too near the young orchard. For the first few years after setting out the 



FIG. 4. Flat-headed Ap- 

 ple-tree Borer; a, Borer; 

 b, pupa; d, adult beetle. 

 (From U. S. Dept. Agr.) 



FIG. 2. Root-louse of apple, showing typical 

 root injury (After Stedman) 



FiC. 3. Round-headed Apple-tree Borer; a, Borer; b, pupa; 

 c, adult beetle. (From U. S. Dept. Agr.) 



