448 
ANNUAL REPORT OF NEW-YORK 
HICKORY. LEAVES. 
belonging to the oak, which is perfectly congeneric with it. None 
of the figures in Koch’s works correspond with these insects, and 
the genus to which they pertain is evidently unknown to him. 
But on gathering from different sources the details of the Euro¬ 
pean plant-louse named Quercus, on which the genus Phylloxera 
has been founded by Fonscolomb, we find such a full coincidence 
as to assure us that our insects are congeneric with that species. 
We cannot but deem that the observation of M. Amyot (Ann. Soc. 
Ent. 2d series, v. p. 485), that in that species the three oblique 
veins arise directly from the outer margin of the wings, is inexact, 
as such a structure would be a perfect anomaly among the species 
of this family. Should that character, however, be as stated by 
M. Amyot, our insects would constitute a new genus, since in 
them the usual longitudinal rib-vein from which the oblique veins 
are given off is perfectly distinct. 
2. Puncturing the leaves and sucking their juices. 
167. Hickory gay-louse, Callipterus Caryellus, Fitch. (Homoptera, 
Aphid®.) 
Scattered upon the under sides of the leaves, a small pale yel¬ 
low plant-louse with white antennae alternated with black rings, 
and pellucid wings laid flat upon its back, its abdomen egg- 
shaped, somewhat flattened and with only minute rudimentary 
honey tubes. Length 0.12. See Transactions, 1854, p. 869. 
This and the four following species of very small delicate 
bright-colored plant-lice inhabiting hickory leaves were described 
in my First Report, at which time I remarked that they with 
other similar insects occurring on oaks and other trees formed a 
group so very distinct from the common species of the genus 
Aphis that they would probably be regarded as entitled to the 
rank of an independent genus. The same year in which that 
Report was published the portion of M. Koch’s beautifully illus¬ 
trated work (Die Pflanzenlause Aphiden) in which a few European 
species similar to these is given, made its appearance. These 
insects are therein formed into a new genus, to which the name 
Callipterus , i. e. beautiful winged, is given. And the European 
C. Juglandicola of Koch appears closely related to this present 
species, though sufficiently distinguished from it by the black 
