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Schizonkura rileyi. Thos. (Eriosoma ulmi, Riley). The Wooly 
Aphis of the Elm-tree. 
This species was originally described and named by Prof. Riley, in 
his first annual report, as Eriosoma ulmi , but as this specific name is 
preoccupied by Aphis ulmi of Linnaeus, which was afterwards trans¬ 
ferred to Eriosoma by Sir Oswald Mosley, and as the two appear to 
be distinct, it is necessary to give this another specific name; I have 
therefore named it after the original describer. It is always preferable 
where it is possible to do so, ^;to give these insects specific names? 
which indicate the plant on which they feed, but in this case all the 
changes possible on the scientific name of the elm have been rung; 
two species in fact previous to this having received the name of Aphis 
ulmi , the second by Ratzburg, which has since been transferred to 
Tetraneura. 
This species, which is quite common in this State, occasionally does 
considerable injury to the white elms which are planted for shade or 
ornament. They usually congregate in clusters on the limbs and trunk, 
causing an unnatural and knotty growth of the wood somewhat similar 
to the knots produced on the roots of the apple tree by the preceding 
species. Their habits so far as observed, appear to be very similar 
to those individuals of E. lanigera which inhabit the trunk of the 
apple-tree. 
The description given by Riley is as follows, which I give in his 
own words, in order to afford the reader an opportunity of comparing 
it with the description of the E. ulmi of Europe. 
Color, dark blue; length to the tip of the closed wing, exclusive of 
the antennae, 0.12 inch; wings hyaline, three times as long as wide, 
and more pointed at the end than E. pyri {E. lanigera). Costal and 
sub-costal veins, and that bounding the stigma behind, robust and 
black. Discoidal veins, together with the third forked and stigmal 
veins, all slender and black, the forked vein being as distinct to its 
base as are the others, with the fork about one-third as long as the 
vein itself, and curved, in an opposite direction to the stigmal vein. 
Antennae, six-jointed, and of the same color as the body; joints 1, 2, 
3, 4 and 0 of about equal length, joint 3 thrice as long as either. 
Legs of the same color as the body. The young lice are narrower 
and usually lighter color than the mature individuals, varying from 
flesh or pink to various shades of blue and purple. The cottony or 
wooly secretion by these lice is very abundant, usually covering them 
from view, and is very white. They generally appear in May or early 
part of June, and by the latter part of June or first of July the 
winged individuals are seen. 
Riley says that for these he has found by experiment, that a wash¬ 
ing with a weak solution of cresylic soap will kill them all instantly. 
He also adds that they are preyed upon unmercifully by a species 
of lace-wing fly, which he names Chrysopa eriosoma. 
The characters of the Aphis ulmi , Linn., Eriosoma ulmi , Sir Os. I 
Mosley, are given as follows by Walker: Dull black; antennae stout, I 
black, moniliform, slightly setaceous, shorter than thegbody; abdomen I 
