120 
tinged with dusky; nervures blackish; stigma rather large, with its 
base and tip whitish ; second cubital cellule oblique ; tergum densely 
punctured on every part; segments on their posterior narrow margins 
white; oviduct about half the length of the abdomen; feet horny 
yellow; intermediate and posterior tarsi white, the joints black at 
their tips; posterior tibiae black, white in the middle. Length one- 
fourth of an inch. Resembles inquisitor , but the posterior mar¬ 
gin of the segments of the tergum are white.” Says’s Entomology, 
Le Conte’s Ed., Vol. II., p. 687. 
THE MAPLE-TREE BARK-LOUSE— Lecanium acericola —Walsh & 
Riley. 
. The soft maple-tree, Acer dasycarpum , Linn, is grown quite exten¬ 
sively in Illinois for shade, owing undoubtedly to the short time 
required for growth. 
They have been infested for the past ten years by a Bark-louse, 
which is easily recognized in the spring months by a white waxy sub¬ 
stance attached to the underside of the limbs, and from the fact that 
the tree is grown in all parts of the state. As but little has hitherto 
been known respecting the life habits of the insect, I have given con¬ 
siderable attention to the study, and here record the result of my 
investigations. 
All Bark-lice belong to the order Hemiptera, sub-order Homoptera 
a,nd family Coccidae. 
The insect under consideration belongs to the genus Lecanium , which 
according to Mons. V. Signoret, of Paris, includes “ species either 
naked or inclosed, or simply covered with waxy, calcareous or filamen¬ 
tous secretions ; and in which the females after fecundation, generally 
acquires an entirely different form to that which she previously pos- 
sesssd, and becomes fixed. Before pregnancy, they have the power to 
move, if necessary.” 
The Lecanium acericola was first recorded by Walsh and Riley, in the 
American Entomologist , vol. 1, page 14, together with illustration. 
They say: “At figure —, we have represented a new species of 
bark louse, Lecanium maclurae , which has recently appeared in con¬ 
siderable numbers on the twigs and leaves of the osage orange, at 
Willmington, Willconnty, Illinois, and also in the vicinity of Alton, 
in South Illinois. 
“The dark part is the scale covering the insect, and this scale, as 
usual in the genus to which the insect belongs, is of a blood brown 
color. The pale part is snowy white, and is composed of a fine cot¬ 
tony down enveloping the eggs and young larvse, which are remarka¬ 
ble for having a longitudinal dark line along the back, had strayed 
away from the parent scale, covering not only the bark of the twigs, 
but also the very leaves. Fitch describes two closely allied bark-lice 
infesting respectively the grape vine and the pear, ( Lee . vitis and 
Lee. pyri ), as having white cotton}^ matter protruding from the tip of 
the scale, as in the species here figured. But in all the specimens of 
these last two species which we have seen, there was nothing of the 
