PERGANDE NORTH AMERICAN PHYtLOXERINiE. 265 



head and rest of the body without a trace of tubercles. The 

 antennae are about one-fourth the length of the body. The third 

 joint is as usual in this genus, the loWer sensorium rather large 

 and more or less circular, the upper one elongated and about one- 

 half the length of the larger or terminal section, which, below 

 the sensorium,, tapers gradually towards its base ; the whole joint 

 is quite densely and sharply serrate. 



This species was found in and about the vicinity of Washing- 

 ton on the leaves of Quercus alba, macrocarpa, panonia and daimio 

 from May till October, the affected leaves of which are speckled 

 all over with small yellow spots, particularly so along the midrib 

 and the smaller veins. The insects causing the injury are found 

 in various stages or forrns on the under side of the leaves. 



It resembles to a great extent Ph. rileyi, though the stem- 

 mother of that species is about twice as large, and the protuber- 

 ances on all parts of its body much longer, while those of the 

 pupae are much smaller on the head and thorax and tubercular 

 on the abdomen. The migratory female is almost one-half smaller, 

 with shorter antennae and wings. 



There can scarcely be any doubt that future careful investiga- 

 tions will disclose the fact that several additional- species will be 

 found infesting our different kinds of oak in various sections of 

 the country, all of them having more or less the same habits. At 

 least five species have been discovered and described in Europe, 

 all of which were found to inhabit various parts of oak trees. 



Phylloxera prolifera Oestl. 



Phylloxera ptolif era Oesil. Synopsis'of the Aphidae of Minnesota, 



p. 16, 1887. 



Mr. Oestlund describes this spefcies in his synopsis as follows: 



"Apterous female.— Co\ov very pale lemon-yellow, smooth, convex 

 above, espjecially in front, tapering behind into a rather long ovipositor. 

 .Eyes, as a very small black spot. Antennae short and fine, 3-jointed : I. 

 0.05mm., 11.0.05mm., III. o.iomm. Beak short and thick, about o.iomm., 

 the setffi very long>hen extended, at least as long as the body, brownish. 

 Legs short ; tarsi with two rather small claws, and with the two capitate 

 hairs as usually in this genus." 



" Wound m-ihegaWsoi ■Pemphigus f(>puiicauHs Fitch during the fall, 



