New Yorxk AGriIcuLTuRAL EXPERIMENT Station. 415 
PLANT LICE.? 
Several species of plant lice attack the apple, but the most 
common in this State is the apple-tree aphis, Aphis malv Fab. 
This is the little, green louse that attacks the buds and leaves in 
the spring. It often occurs in great numbers on the under side of 
the leaves, sucking the sap from the tissues. This irritation causes 
the leaves to curl, thus affording partial protection to the insects. 
The winter is passed in the egg stage. Many generations and 
countless individuals, both winged and wingless, are produced 
during the summer. They secrete a clear liquid (honey dew) 
which sticks to the leaves and twigs and finally turns black, because 
of a black fungus which grows in it. 
Treatment.— The trees should be carefully watched, and, when 
the lice first appear, sprayed thoroughly with a solution of whale 
oil soap and water — one pound to seven gallons. The lice may 
appear any time after the buds burst. It is important to give the 
infested trees at least one or, as is often necessary, two thorough 
applications before the leaves have become curled. It will be very 
difficult to reach the lice when they are protected by the curled 
leaves. ‘The spray should be directed toward the under side of 
the leaves. 
INSECTS ATTACKING TRUNK AND BRANCHES. 
THE WOOLLY LOUSE OF THE APPLE. 
(Schizoneura lanigera Hausm.) 
This insect is easily detected by the white wool-like substance 
which the lice secrete and which clings to their bodies. They 
attack both the roots and young branches causing gall-like swell- 
ings. ‘They are especially injurious to young trees and sometimes 
do serious injury to new grafts. 
Treatment.— When occurring upon the roots considerable 
relief will usually result from the application of finely ground 
9 For a further discussion of plant lice, see Bulletin 139 of this Station, by 
V. H. Lowe. 
