226 PESTS OF ORCHARD AND SMALL FRUITS 
and garden crops, and is discussed under the heading ‘‘ White Grubs, ” 
in the section on Insect Pests of Garden and Field Crops, page 109. 
The Woolly Apple Aphis (Schizoneura lanigera Hausm.) 
The woolly aphis is found both on the larger twigs or limbs and on 
the roots of apple trees. It is characterized by a white, fluffy secre- 
tion, looking like little masses of cotton. On the twigs it is found in 
Fic. 282.—Apple root showing characteristic work of the 
Woolly Apple Aphis. Original. 
clusters on the more tender bark, especially at the axils of twigs or 
where there has been some break in the bark, or on water sprouts. 
Its work here results in a swelling, which is apt later to crack open. 
On the roots the attack causes knotty enlargements. The root forms 
are the more serious, because of interfering with the normal functions 
of the roots. Attack is especially severe on newly set trees, which are 
less able to withstand injury. 
For the greater part of the year the lice are wingless. Toward the 
end of summer winged individuals are developed, and these fly to 
new hosts, where, after a succeeding sexed generation, eggs are laid 
in crevices of the bark. Hibernation is accomplished both by these 
eggs and by the subterranean colonies. 
For the lice working above ground spray with tobacco extract or 
with 7 per cent kerosene emulsion. Apply the material with con- 
siderable force. For those beneath ground draw back the earth from 
around the tree to a distance of 2 or 3 feet and a depth of 4 
