B37 
are apt to become extremely numerous, so as to injure even large 
trees very seriously, causing the infested leaves to turn gradually 
brown and to drop after most of the insects have left. This injury to 
the foliage of badly infested trees or shrubs, as a rule, is very severe 
on the branches, many of which gradually dry up and die, which 
injury, if continued for a number of years, will kill the irees. The 
development of the second generation of the gall-inhabiting insects, 
which eventually become winged, is also rapid, to enable them to 
attain full development before the leaves commence to drop and 
to be ready for return migration to the witch-hazel early in June, to 
give birth to the final or sexed generation, to complete the cycle of 
existence of the species. This 
is the generation described by 
Mr. O. W. Oestlund in his 
‘‘Synopsis of Aphid of Min- 
nesota,” under the name of 
Hormaphis papyracee. 
Fourth generation, _ first 
stage (Fig. 20).—The general 
appearance of the leaf-corru- 
gating generation has so com- 
pletely changed as to bear no 
resemblance whatever to the 
previous coccidiform genera- 
tion; so much so as to render 
it impossible to detect their 
affinity or their close relation- 
ship except by continued and 
close observation; which I 
have been so fortunate as to 
trace without the shadow of a Pit, % Hamenaste mincw & Young Jarre 
doubt. c,antenna; d, eye; e, adult female, dorsal view; f, 
ventral view; g, antenna—much enlarged (origi- 
nal). 
The young larve when first 
deposited are of an orange 
color, but soon change to yellowish-brown; marked with two broad 
and faintly dusky stripes on the head, which extend to the prothorax. 
The eyes are purplish, with three colorless ocelli. Antenne and legs 
dusky. They are elongate-oval, slightly convex, distinctly segmented, 
and 0.5 to 0.5™™" in length. The head is broader than long and semi- 
circular in front, where it bears four short bristles arising from small 
tubercles; two similar bristles are each side of the thoracic, one each 
side of the abdominal segments, and four along the edge of the broad 
and semicircular tail. There appears to be also a transverse row of 
four short bristles on the thoracic segments and two, medio-dorsally, 
on the abdominal segments. The antennz are four-jointed; the two 
basal joints short and subequal in length; the two last joints long 
