PERGANDE NORTH AMERICAN fHYLLOXERIN-*:. I95 



Phylloxera carycefolioe Riley. Seventh Ann. Rep. Nox. and Ben. 

 Ills, of Mo., p. 117. 



Phylloxera carycefolice Thomas. Eighth Rep. Nox. and Ben. Ins. 

 of Ills., p. 161. 



Notwithstanding the apparently wide distribution of this species 

 from New York to Illinois and as far south as Washington, it 

 appears to be nowhere so common or so destructive as some of its 

 near relatives. It is most noticeable during the latter part of 

 May on the leaves of Hicoria glabra, and though usually there is 

 but a single gall upon a leaf, as many as four may sometimes be 

 found. Some which were studied on the 23d of May along the 

 Potomac River in Virginia contained already quite a number of 

 winged migrants, though the gall had not yet sufficiently opened 

 at the apex to allow the inmates to escape. 



The principal part of the gall is always on the upper side of the 

 leaf and represents a regular, slender cone which often leans 

 slightly over to one side. The transeverse diameter of the gall 

 at the base of the cone is about 3""- and, including the pale ring 

 surrounding it, about 5"""-; and its vertical diameter is also about 

 ^n.m. j(-s surface is more or less pubescent, more densely so 

 beyond the middle. Its color above is pale green, with numerous 

 still paler, extremely fine, radiating lines running from tip to 

 base. The apex is either somewhat somewhat yellowish, pale 

 brownish or pale purplish and the extreme base darker green. 

 The ring surrounding its base is either somewhat projecting and 

 slightly convex or sometimes depressed or saucer-like and of a 

 yellow or greenish-yellow color. The under side of the gall is but 

 slightly projecting and quite flat, with a small elevated ring sur- 

 rounding a minute central depression from which rises a small 

 nipple, splitting into a number of very fine and slender pubescent 

 filaments. The walls of this gall are very thin and flexible and 

 rather difficult to tear, especially when they commence to shrivel 

 after having been taken off the tree for some time. They are 

 stoutest at base and more or less transparent if held towards the 

 light. That this species is closely related to Ph. c.-septum is quite 

 apparent. The younger ones have also, as in that species, a trans- 

 verse membrane which gradually disappears, leaving a distinct 

 rim to indicate its position. 



