10 
at base with a purplish or vinous ring, which is also more or less dis- 
tinet on the underside. By the middle of May the galls are about 
two-thirds grown, showing the peculiar conical formation clearly and 
reaching full development toward the end of May, when they measure 
from 10 to 12™™ in length by4 or 5™™ in diameter at base. They are 
obliquely conical, or of the shape of a dog’s tooth, and somewhat con- 
stricted at base, the underside forming an elevated and rather stout 
rim around the more or less circular opening which is densely covered 
with a pale pubescence. The opening has by this time become large 
enough to allow the migrants to escape. They are now of a firm, 
leather-like consistency and of a uniform pale yellowish-green or 
greenish-yellow color. 
If not numerous, as in 
some years, there is 
generally but one or at 
most two galls on a 
leaf, whereas in favor- 
able years there may 
be from two to eight or 
more galls on a single 
leaf, which then be- 
comes more or less 
dwarfed and much dis- 
torted. These galls, 
even after their archi- 
tects have departed, 
remain fresh and sue- 
culent for a considera- 
ble length of time, but 
gradually turn brown 
and dry up. 
Winter egg.—The 
winter eggs of this 
Aphid, as in some other 
species of plant-lice inhabiting trees and shrubs, are deposited on the 
branches and twigs, especially those bearing the leaves, and generally 
around or near the base of the buds or near the sears left after the 
dropping of the leaves in October, or as late as any of the leaves bear- 
ing the sexed generation remain on the shrubs. The eggs resemble 
greatly those of Aphis mali, though they are considerably smaller, and 
measure about 0.2"" in length. They are of a slightly pyriform shape, 
bluntly pointed at the posterior end and highly polished, being at first 
yellowish or orange but changing gradually to a deep black. 
© 
/ 
Fic. 1.—Hormaphis hamamelidis: a, galls, natural size; b, sec- 
tion of gall—much enlarged (original). 
FIRST GENERATION. 
Stem-mother, first stage (Fig. 2).—The young stem-mother on hatch- 
ing is but slightly larger than the egg, and makes her appearance 
