FIELD BOOK OF INSECTS. 



Leaves 



Hormomyia verruca: about . I inch in diameter, on veins ; 

 about evenly divided by the leaf, the upper side flattish 

 or with a minute nipple, the lower side wart-like. For 

 Pontania pomum see Fig. 7, on midrib. P. pisum: pea- 

 like, yellowish, on under side of leaves. P. desmodioides: 

 smooth, flattish, sessile, yellowish-green, about equally 

 divided by the leaf. P. hyalina: fleshy, reddish, in parallel 

 rows on either side of the midrib. P. borealis: solitary, 

 smooth, reddish, pear-shaped, about one-third above the 

 leaf. P. consors: gregarious, hairy, rather spherical, near 

 leaf -base, about one- third above the leaf. P. gracilis: 

 spherical, smooth, near petiole to one side of midrib, about 

 equally divided by leaf. P. terminalis: green swelling on 

 upper surface; the leaf eventually rolls. 



Plate XCV. The principal twig-gall is 

 ickory Phylloxera caryacaulis (Fig. 13). Numerous 



other species of Phylloxera make galls on the leaves. Of 

 these the petiole bears caryaren, kidney-shaped; sub- 

 elliptica, elongate, nut-like; and spinosa, irregular, spiny 

 galls. On the leaves, those of cary<zyen<z are keel-like 

 pleats along the leaf- veins; caryafallax crowded, conical, 

 on upper surface; deplanata, reddish- or greenish-yellow, 

 conical below; depressa, depressed, fringed; pilosida, 

 hairy, light green, flattened above, below convex and with 

 a nipple. The galls of Caryomyia holotricha (Fig. 8) are 

 pubescent; carycscola (Fig. 9), smooth; sanguinolenta 

 (Fig. 10), red; tubicola (Fig. n); and persicoides (Fig. 12), 

 brownish, downy. C. cynipsea makes a round, hard, 

 midrib gall, about half an inch across. C. nucicola de- 

 forms the husks. 



Dasyneura serrulatcz causes deformations, 

 Alder with whitish "bloom," of terminal buds 



(Plate XCV, Fig. 2). 



460 



