44 The Ohio Journal of Science [Vol. XVI, No. 2, 



half an inch long. In July, pale yellowish and contained in 

 several small hollows, minute whitish larvse, with breast bone 

 narrowed anteriorly and ending in a point." Osten Sacken. 



This form is so different from the other itonid galls of the 

 hickory that the writer is inclined to place it here tentatively. 

 It is very similar to Phylloxera caryavencB Fitch, with the 

 exception that the hyperplasia extends below the leaf, while 

 in the phylloxera gall it is developed on the upper side. The 

 writer has observed orange colored larvae in the aphid galls, 

 but they were not definitely determined to be itonid. 



Since this type of gall has not since been reported as 

 definitely caused by itonid larvae, it is barely possible that 

 Osten Sacken described the empty phylloxera gall above 

 mentioned containing inquilinous itonid larvse. The writer 

 found many of these galls deserted by the aphids in the middle 

 of July and Pergande states that the aphid nymphs begin to 

 leave the galls in July. At this time, these galls are a "pale 

 yellow" color as described for the "cynipsea" gall. The 

 writer's observations were made in southern Ohio, while Osten 

 Sacken's were made in the vicinity of Washington, D. C. 



Osten Sacken, Lowe's Monogr. Dipt. N. Am. Pt. 1. p. 193. 1862. 



5. Cecidomyia sp. 



Leaf, under side, double chambered conic or depressed 

 (Fig. 5a) gall. The latter condition is perhaps the more usual. 

 In these forms, the conic tip is sunken in the central fovea, the 

 gall only measuring from 13^-2 mm. vertical diameter. The 

 conic forms are as though the tip was pulled out destroying the 

 fovea. These often measure 5 mm. in height. The width of the 

 galls varies from 3-5 mm. Very light green, or when older yellow 

 to red, surface roughened with low tubercles as seen with lens. 

 Inner chamber sub-conic with short mucronate tip. Walls of 

 both chambers thin and smooth, outer wall slightly sticky. 

 Base of gall flat, arising from a definite pedicel, resting in a 

 cup-like depression, which is formed in a definite hyperplasia 

 intercalated in the leaf. Above, this hyperplasia is evident 

 as a raised circular area, 2Y2 mm. diameter, in the center of 

 which is a minute light colored papilla. 



Rather common on IJ. alba. Collected in Hocking and 

 Athens counties, Ohio. 



