Aphids Injurious to Orchard Fruits, Ete. 13 
THE WOOLLY APPLE APHIS." 
The woolly apple aphis is often in evidence in summer on the 
trunk, branches, and twigs of the apple as bluish-white cottony 
patches (fig. 8) which hide the rusty or purplish brown aphids 
beneath. While principally injurious to the roots of the apple, its 
injuries above ground are at times quite important. In orchards 
grown under arid or semi-arid conditions in the West it is decidedly 
more troublesome than in the East, attacking the tree wherever the 
bark is tender and sometimes infesting the stems of the leaves and 
fruit. Its injuries above ground often result in galls or swellings 
similar to those on the roots, and when the fruit spurs are invaded 
the fruiting capacity of the tree may be interfered with seriously. 
fi ae 
ani 
~@ - 
(g 
Peres % 
nae 
/ ¢ . 
g ; 
Ty! Tan H coy = 
JSS te = sane CIEE aa ere 
Fic. 7.—The clover aphis: a, Spring migrant; b, stem mother; c, antenna of spring migrant; d, antenna 
of wingless form; e, cornicle of spring migrant; /, cauda of spring migrant; g, cornicle of wingless form; 
h, cauda of wingless form. a, 6, Much eniarged; c-h, more enlarged. 
The usual contact sprays will be effective in destroying this pest on the 
limbs and branches. Its treatment on the roots of the apple requires 
essentially different methods, which are not considered in this bulletin. 
APPLE APHIDS OF MINOR IMPORTANCE. 
Several additional species of aphids are found upon the apple, but 
these are at present of minor economic importance. 
The potato aphis? has been found feeding upon the apple occa- 
sionally in thespring. Its normal winter host appears to be the rose. 
This form is very much larger than the others mentioned, and the 
winged form, as well as the wingless one, is uniformly light greenish. 
1 Friosoma lanigerum (Hausm.). 2 Macrosiphum solani/olii (Ashm.). 
