10 Bulletin 2: Spkixgfield Museum. 



Ectoedemia populella Busck. 



Ectoedemia populella Busck, I'roc. Ent.soc. Washington, 1907, v, 8, p. 97-99. 



This subglobular, one-celled gall is found on the petiole at its union 

 with the blade of the leaf. There are distinct longitudinal ridges. Color 

 like that of the petiole. About 5-7 mm. in diameter. The cell-walls are 

 1-2 mm. thick. Very abundant on American aspen, Populus tremuloides. 

 In October the larvae go down to pupate in the ground. The moth 

 emerges in May. 



Salix. 

 Eriophyes aenigma Walsh. Willow mite gall. Fig. 8. 



Cecidomyia salicis-aenigma Walsh, Proc. Ent. soc. Phil., 1864, v. 3, p. 608-610. 

 Acarus salicis-aenigma Walsh, Proc. Ent. soc. Phil., 1866, v. 6, p. 227. 



Deformation of leaf or flower bud. Polythalamous, irregular mass 

 both in size and shape. 1-3 cm. long. Like a woolly tangle of aborted 

 flower parts. Silvery to ash gray in color. Appears in early summer 

 (June). On willow, Salix. 



Eriophyes semen Walsh. Willow seed gall. 



Cecidomyia solids -semen Walsh, Proc. Ent. soc. Phil., 1864, v. 3, p. 606 60S. 

 Acarus solids-semen Walsh, I'roc Ent. soc. Phil., 1S66, v. 6, p. 226-227. 



Cook, 29th ann. rept. Dept. geol. and nat. res. Indiana f. 1904, 

 1905, p. 858. 



A small, monothalamous, sac-like, rounded gall. About 1 mm. in 

 diameter. Usually on upper side of the leaf with the opening below. 

 Found in large numbers on the leaf affected. Begins in early summer, 

 matures with the leaf. On willow, Salix. 



Cecidomyia verruca Walsh. 



Cecidomyia salicis-verruca Walsh, I'roc Ent. soc. Phil., 1864, v. 3, p. 606; 1866, v. 6, p. 226. 



Monothalamous, subspherical gall on midrib or veins of leaf. Projects 

 very slightly on upper surface, much more on under surface where the 

 insect emerges, apparently, from a neat round hole. (This latter char- 

 acteristic, so distinct from Walsh's description, has made me mistrust my 

 identification.) On two species of willow, Salix. Late summer. 



Mayetiola riyidae Osten Sacken. Willow club-gall. Fig. 9. 



Cecidomyia salicis Fitch, Airier, quart journ. agr. and sci., 1845, v. 1, p. 263. (Nomen praeoc.) 

 Cecidomyia rigidae Osten Sacken, Mon. X. A. dipt., 1862, pt. 1, p. 189. 



Walsh, I'roc. Ent. soc. Phil., 1864, v. 3, p. 594-597, 



Riley, Amer. ent. and hot., 1870, v. 2, p. 214, tig. 133. 



Cook, Ohio nat., 1903, v. 3, p. 422, tig. 42. 



Jarvis, 37th ann. rept. ent. soc. Ontario, 1906, p. 68. 

 Mayetiola ri<ji<l<i<- Felt, 23d rept. ins. X. Y. f. 1907, 1908, p. 357, 371. 



Monothalamous, irregularly conical, twig-gall, sometimes terminal, 

 frequently with a twig growing from its side, always with several buds on 

 sides. It is tipped with a hollow bud which looks as if it had died early 

 in the development of the gall. Reddish brown, grooved lengthwise. 

 About 2 cm. long. Larval cell extends the length of the gall. On common 

 willows. Common. Insect remains as larva during winter, pupates in 

 spring, soon emerges through terminal beak. 



