444 
ANNUAL REPORT OF NEW-YOR.lt 
RICKORY. L RAVES. 
AFFECTING THE LEAVES. 
1. Fanning galls and other excrescences . 
1163.. Hickory-stem gall-lousk, Pemphigus Carytzcaulis , Fitch. (Ilomop 
tera. Aphides.) 
Forming bullet-like galls, hollow, green and of a leathery tex¬ 
ture, upon the leaf stalks and succulent young shoots, with the 
walls of the cavity inside covered with minute white and yellow 
lice; the perfect, winged insect not yet discovered; the gall sub¬ 
sequently turning black, opening and becoming cup-shaped. See 
Transactions, 1854, p. 859. 
164. IIickory-vein gall-louse, Pemphigus 1 Caryavencs, new species. 
Forming plaits in the veins of the leaves, which project up 
from the surface in an abruptly elevated keel-like ridge upon the 
upper side of the leaf and with a mouth opening on the under 
side, the lips of which are woolly and closed. 
Although the Aphis which produces these plans in the veins of 
hickory leaves is unknown to us in its winged state, its work will 
suffice to distinguish it. from other species. The plaits occur 
mostly near the middle of the leaf, upon one side of the mid-vein, 
occupying the bases of the lateral veins, two or three of which 
are commonly enlarged into these excrescences or galls, which jut 
up in keel-like ridges from a quarter to a half inch in length. 
These ridges are of a pale yellow color, turning brown and be¬ 
coming dry and dead after a time, and frequently before they 
perish the portion of the leaf between them withers and turns 
brown, in which case the inhabitants of the gall forsake it, being 
no longer able to obtain a due supply of nourishment from its 
walls. The lips of the mouth which opens on the under side of 
the leaf are covered with white or pale tawny yellow wool. They 
are pressed together, but a small orifice is open at their outer end, 
through which some of the young lice frequently crawl from the 
interior of the gall and station themselves upon the under surface 
of the leaf by the side of the mid-vein. The lips are readily 
drawn apart, exposing the cavity within, the walls of which are 
covered with minute wingless females and their eggs and young. 
The females are egg-shaped, broadest anteriorly and tapering 
behind to an acute but not an attenuated point. They are 0.03 
