3 
known in India and Chile, and probably is as widespread as are any of 
the common injurious fruit pests. Notwithstanding the possibility of 
its being a native American insect, it did not attract attention in this 
country much before 1850. Its spread since has, however, been rapid, 
and it now occurs practically wherever the apple is grown. It has been 
reported to this Division from no less than thirty-five States and Terri- 
tories and nearly one hundred localities. It is particularly abundant 
and injurious in the latitude of the Ohio Valley. While seemingly, 
therefore, somewhat affected by severe cold, it is able to thrive in the 
climate of the northern tier of States on the one hand and in that of 
Louisiana, New Mexico, and southern 
California on the other. 
NATURAL HISTORY AND HABITS. 
In common with most plant-lice, 
this species has a complicated life 
history, some of the details of which 
are still lacking. The common forms 
both on the roots and above ground 
are wingless lice, not exceeding one- 
tenth of an inch in length, and of a 
reddish-brown color, and abundantly | 
covered, especially in the aerial form, 
with a flocculent waxy excretion. 
These are so-called agamic females, 
and reproduce themselves by giving 
birth, as observed by many entomol- 
ogists, to living young indefinitely, 
perhaps for years, without the inter- 
vention of other forms. The newly 
born larve have none of the white 
excretion, which, however, soon ap- 
pears as a minute down when they Fia. 2.—Woolly aphis (Schizoneura lanigera): 
< é . a, root of young tree illustrating deforma- 
begin to feed. These lice are also tion; 6, section of root with aphides clus- 
peculian ame lacking the» honey-tubes  ‘™¢4 over it; ¢, root louse, temale—a and 
‘ ; b. natural size; c, much enlarged (original). 
common to most aphides, but exude 
the honeydew from the tip of the body. In October or November, or 
earlier in the South, among the wingless ones, numbers of winged indi- 
viduals appear, which are also all females, and are the parents, as 
shown by the observations, partly unpublished, of Messrs. Howard and 
Pergande, of a true sexed generation of minute, wingless, larviform lice, 
the females of which, as in the case of the grape root-louse, give birth 
to a single “ winter egg.’’ This egg is attached within a crevice of the 
bark, and, probably, following the analogy of the phylloxera, hatches in 
the spring into a female aphis which originates a new aerial colony. 
