POPLAR-LEAF APHIDS. 471 



54. The poplar-leaf apuis. 



Aphis popullfolice Fitch. 



Inhabits the underside of the leaves of Populds grandidentata. Of a chestnut-brown 

 color, mealy; legs hairy, black, pale browu above the knees; veins of the forewings 

 brown, stigma smoky yellow, margined with black ; back with two rows of impressed, 

 squarish fnscous spots; on each side, two rows of impressed dots; honey-tubes equal- 

 ing a third of the distance to the tip. Length 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 imperfectjy 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. 



