POPLAR-LEAF APHIDS. 
471 
54. The poplar-leaf aphis. 
Aphis popidifolice Fitch. 
Inhabits the underside of the leaves of Populu? grandidentata. Of a chestnut-brown 
color, mealy; legs hairy, black, pale brown above the knees; veins of the fore wings 
brown, stigma smoky yellow, margined with black ; back with two rows of impressed, 
squarish fuscous spots; on each side, two rows of impressed dots; honey-tubes equal- 
ing a third of the distance to the tip. Leugth to tips of wings .22 inches. (Thomas, 
3 Rt. Ins. 111.) 
Fig. 170.- The Poplar-stem Gall-Louse. Marx del 
55. The poplar-stem gall louse. 
Pemphigus popuUcaulis Fitch. 
Forming imperfectly globular galls the size of a bullet at the junction of the leaf 
with its stalk, these galls having a mouth-like orifice on their underside, and a large 
cavity within, crowded with small dull white lice and their white cast skins, and with 
winged lice of a blue-black color, their antennae reaching beyond the base of their 
wings, the rib-vein of their fore wings black, thick, much thicker at its apex along 
the inner margin of the stigma, and the short veinlet bounding the anterior end of 
this spot more slender than the rib-vein ; its length 0.10, and to the tips of its wings 
0.15. (Fitch.) Observer at Maine and in Rhode Island. 
