oo 
Insects of Shade Trees and Their Control. 87 
Remedies.—Since it is not a dangerous insect and treatment of large 
trees is usually costly, it is not imperative to do anything. Under 
certain conditions there might be justification for either destroying 
or treating alders in the neighborhood, and the maple trees, of course, 
may be treated direct. Both kerosene emulsion (p. 12-13) and 40 per 
cent nicotine sulphate (p. 18) are efficient agencies for killing this 
pest. 
Fie. 61.—Woolly beech aphis on underside of leaves. 
BEECH-TREE BLIGHT APHIS” AND WOOLLY BEECH APHIS.” 
How injurious —While not a menace to the life of trees, the beech- 
tree blight aphis and woolly beech aphis frequently occur in such 
abundance as not only to mar the appearance of the trees but also to 
kill twigs and young trees. The woolly beech aphis (fig. 61) is found 
to be specially abundant on copper beech leaves. 
How recognized —The masses of bluish-white woolly aphids on the 
underside of the limbs are the beech-tree blight aphis and those on 
the underside of the leaves are the woolly beech aphis. 
® Prociphilus imbricator Fitch. ®& Phyllaphis fagi L. 
