PLANT LICE FEEDING ON THE ROOTS 229 
The Black Peach Aphis 
(Aphis persice-niger Er. Sm.) 
The roots of peach trees often become infested 
with a soft-bodied, black plant louse. Usually 
a few of the same lice will be found on the leaves 
as well, but often the only visible evidence of 
attack is the yellowing of the foliage and 
general unthrifty 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 lice. 
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 foliage may be 
killed by spraying thoroughly with tobacco ex- 
tract or 7 per cent kerosene emulsion. 
The Strawberry Root-louse (Aphis forbest 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 
Fig. 287.— The Black 
Peach Aphis. Lice 
clustered on root. 
Original. 
up, clusters of the lice will be found on the roots, always in com- 
pany with ants. 
The ants are responsible for the root infestation. The lice 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 above ground; then the ants appear and carry the lice 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 
