PLANT LICE FEEDING ON THE ROOTS 



229 



The Black Peach Aphis 

 {Aphis jjersicoB-niger Er. Sm.) 



The roots of peach trees often become infested 

 with a soft-bodied, black plant louse. Usually 

 a few of the same hce will be found on the leaves 

 as well, but often the only visible evidence of 

 attack is the yellowing of the fohage and 

 general untlirifty appearance of the tree. Ex- 

 amination will disclose large numbers of these 

 insects clustered on the roots. When mature, 

 they are shining black, and the body is more 

 nearly round than that in most plant Hce. 

 The younger forms are brown or reddish. 



Treatment consists in drawing away the earth 

 from around the base of the tree and applying 

 3 or 4 pounds of tobacco dust, replacing the 

 earth afterwards. The lice on fohage may be 

 killed by spraying thoroughly with tobacco ex- 

 tract or 7 per cent kerosene emulsion. 



The Strawberry Root-louse {Aphis forbesi Weed) 



Dark greenish or bluish, soft-bodied plant lice 

 infest the roots of strawberries. Where beds 

 are badly attacked, patches are killed out here 

 and there. If a plant that is unthrifty is pulled 

 up, clusters of the hce will be found on the roots, always in com- 

 pany with ants. 



The ants are responsible for the root infestation. The hce hatch 

 early in the season from eggs laid in the fall on the stems and leaves 

 by the last generation of the previous year. Two or three generations 

 are passed alcove ground ; then the ants appear and carry the hce to 

 the roots, later transporting them to other plants as the ones infested 

 sicken and die. 



An effective treatment consists in covering the plants with straw in 



Fig. 287.— The Black 

 Peach Aphis. Lice 

 clustered on root. 

 Original. 



