Insect Galls. V 



Populus deltoides. 

 Pemphigus vagabundus Walsh. 



Byrsocrypta vagabunda Walsh, Proc. Ent. soc. Phil., 1862, v. 1, p. 306307; 1864, v. 2, p. 462. 

 Pemphigus vagabundus Walsh and Riley, Amer. ent., 1868, v. 1, p. 57; 1869, v. 1, p. 107108. 

 fig. 87-88. 

 Packard, Guide study ins., I860, p. 524, fig. 522,525. 

 Oestlund, Bull. 4. Geol. and nat. hist. surv. Minn., 1887, p. 22. 

 Cook, Ohio nat., 1904, v. 4, p. 118,140, fig. 112; 29th aim. rept. Dept. 

 geol. and nat. res. Indiana 1". 1904, 19 5, p. 850-851, fig. 43, 

 Jarvis, 37th ann. rept. Ent. soc. Ontario, 1906, p. 63. 



A deformation of the terminal bud with the leaves so changed as to 

 lose all appearance of leaves, each becoming bag-like, sonic like cock's 

 combs. Yellow-green, becoming nearly black in winter. Persistent. 

 Very common. On poplar, Populus deltoides. 



Populus grandidentata. 

 Mecas inornata Say. Poplar twig gall. Fig. 2. 



Saperda inornata Say, Journ. Acad. nat. sci. Phil., Is23, v. 3, p. 407. 



Walsh, Proc. Ent. soc. Phil., 1867, v. 6, p. 264. 

 Mecas momata Packard, 5th rept. U. S. ent. comra., 1S9(), p. 427-42S, fig. 156. 



Irregularly spherical swelling of the twig, 1-3 cm. in diameter. At 

 first smooth, pithy, in second season becomes cracked without and hollow 

 within. Beetle bores its way out in May. On Popxdus grandidentata 

 and P. tremuloides. 



Cecidomyia? irregularis, n. s. > 



Irregular, monothalamous, blister-galls, between veins. Usually more 

 than one on a leaf. Projecting above mainly, presence indicated below by 

 a light-colored, roughened space. On large-toothed aspen, Populus grand- 

 identata. Not rare. 



Populus tremuloides. 



Pemphigus? rileyi n. s. Poplar cluster-gall. Fig. 3. 



A spherical, red and yellow gall occurring in clusters, usually on the 

 under side of the leaf, near the petiole. Above there is a conical projec- 

 tion at the top of which is the opening. Thin-walled. About 5 mm. in 

 diameter. On aspen, Populus tremuloides. Rather common. 



Mecas inornata Say. See above. 



Agromyza simplex Loew. 



Agromyza simplex Loew, Dipt. Amer. septentr. indig., centur. viii, p. 84. (Berl. ent. 

 zeitschr., 1869.) 



An irregularly oval, rough gall occuring singly or two in line on the 

 twig. Color of the bark. About 8 mm. long, 4 mm. wide. Polythala- 

 mous. On American aspen, Populus tremuloides. 



(This is apparently the same gall as is attributed to Agromyza 

 aeneiventris Fallen by Jarvis (38th ann. rept. Ent. soc. Ontario, 1907, p. 

 85-86, pi. A, fig. 8), but the imago reared from a Springfield gall answer- 

 ing the same description has been pronounced by Mr. C. W. Johnson, of 

 Boston, to be Agromyza simplex.) 



