ants to the roots of the corn plants as the weeds in the held are de- 

 stroyed by cultivation, and there they continue to multiply the whole 

 season thru. 



11. The corn root-louse may live and propagate thru the sea- 

 son on a considerable variety of other plants, including several com- 

 mon weeds, but on none of them in numbers to make the fact a matter 

 of serious economic importance. Injury to corn by root-lice is alinost 

 wholly due to those which have fed and bred in fields of corn, and not 

 to the comparatively scanty stock which lives on other plants. From 

 this it appears that if they are generally prevented from getting a start 

 in corn fields in spring, their injury to corn will be insignificant. 



12. The root-lice may be most easily destroyed in early spring, 

 and a strong check may also be put upon the multiplication of the 

 corn-field ants by early plowing of old corn fields to a depth of six or 

 seven inches, followed by repeated deep disking as a preparation of the 

 ground for corn. This treatment acts by killing and keeping down 

 the young weeds on which the root-lice are feeding, and by breaking 

 up the burrows of the ants and scattering the eggs and young of the 

 root-lice and the eggs and young of the ants themselves thru the dirt 

 so thoroly that the ants can not recover their property even if they 

 remake their nests. 



13. As corn planted on ground not in that crop the year before 

 may become infested by winged root-lice from neglected fields of last 

 year's corn, anything like a general control of the injury requires a 

 general clearing up of old infested fields in spring. So far as possible, 

 any such fields should be treated as prescribed under No. 12, both as 

 a protection of one's own corn crop, which is likely to be first and 

 most heavily infested, as a rule, by the root-lice of one's own raising, 

 and also as a duty to one's neighbors, whose crops should not be left 

 to suffer injury because of one's own negligence. 



14. When this program of preventive preparation of old corn 

 fields can not be fully carried out. some temporary advantage may 

 sometimes be gained in the beginning by planting with the seed sub- 

 stances so ofifensive and repellent to the ants that they will keep out 

 of the hill until these have disappeared. Such substances are oil of 

 tansy, tincture of asafetida, oil of sassafras, anise oil, kerosene, oil of 

 lemon, and a number of other volatile oils and strong-smelling sub- 

 stances, the vapors from which the corn-field ants can not endure. 

 These fluids were formerly used by mixing the seed with them direct. 



