852 
ANNUAL REPORT OF NEW YORK 
POPLAR. LEAVES. 
base of the leaf, but sometimes in its middle. Among the insects in the 
cavity inside may be found the larvae, pupae and perfect insects of both 
sexes, which sexes can be distinguished in all the stages of their growth by 
their colors, the females being dusky and the males dull green with whitish 
legs and antennae. A single wingless individual, larger than any of tho 
others in the gall, is the parent or at least the progenitor of the entire 
family. As an instance of the tenacity of life which insects possess in 
their pupa beyond any other period of their existence, it may be observed 
that a wingless female with a larva and a pupa of this species, having been 
attached with gum to a slip of card, the two first were noticed twenty-four 
hours afterwards dead and shrivelled to mere shapeless specks, whilst the 
pupa remained alive, plump and strong, actively engaged in efforts to break 
its feet from the dried gum wherein they were fettered. 
The female LARV.E are dusky on tho body and legs, with a tuft of white flocculcnt cotton¬ 
like fibres projecting backward from the end of the body, and a coating of white mealy powder 
over the rest of the surface. They are quite small, measuring about 0.025 in length, straight 
along each side and slightly narrowing from behind forward. 
The MALE LARvas are less numerous than those of the female and double their sizo. They 
are very pale dull green with whitish antennas and legs, the feet sometimes slightly dusky. 
They are coated with white meal and tufted at tho tip like the female, but their bodies are 
more tapering forward and show the impressed sutures quite distinct. 
Tile male PUP.E are oval with tho head and first, segment of tho thorax narrower. They 
are dull pale green with tho second segment of the thorax and tho wing-scalcs paler and 
watery in their appearance, and the suturos of the abdomen less distinct Than in the larvto, 
which they slightly exceed in their sizo. 
The female pupa, are dusky like their larvto, with the wing-scalcs and the thorax 
between them of an obscure whitish or pale watery color. 
Tho WINGLESS female, the parent of the colony, is as broad as long, measuring 0.04 to 
0.05 in length, the hind end being usually concave or notched, and the abdomen elevated or 
humped in its middle, resembling that of some spiders. She is pale dusky with two rows of 
snow white dots formed of a mealy or pruinose substance, along each side of tho back, the 
dots of tho inner row being more numerous. Her head is darker and her legs dull pale yel¬ 
lowish with the feet dusky. 
As some of the gall-lice now described may every year be met with upon 
the poplars planted in the grounds around our dwellings, I have given a 
somewhat extended account of them, thinking some of the persons into 
whose hands this Report will come, will, with the aid thus furnished them, 
be curious to examine these insects, whose habits are in many respefcts so 
interesting and truly remarkable. In addition to those which have now 
been noticed, several other species of the Aphis family dwell more openly 
exposed upon the leaves and green twigs of our poplars. I refrain from 
presenting these and similar insects belonging to oaks and other trees, until 
I shall have re-examined them in their living state, and compared them 
with the figures in the beautiful Monograph of Koch, that I may assure 
myself more fully whether several of them be not, as I suppose them, iden¬ 
tical with those occurring upon similar vegetation in Europe. 
