no NEW YORK STATE MUSEUM 



1873 Riley, C. V. Nox. & Other Ins. Mo., 5th Rep't, p. 1 14-16 (Cecidomyia) 



1874 Glover, Townend. MS. Notes from My Journ. Dipt., pi. 9, fig. 17 

 (Cecidomyia) 



-1 883-1 889 Saunders, "William. Ins. Inj. Fruits, p. 295-96 (Cecidomyia) 

 1892 Beutenmueller, William. Am. Mus. Nat. Hist. Bui. 4:272 (Cecidomyia) 

 1899 Smith, J. B. List Ins. N. J., p. 621 (Cecidomyia) 

 1904 Beutenmueller, "William. Am. Mus. Nat. Hist. Guide Leaflet 16, p. 32 

 (Cecidomyia) 



Y. State Mus. Bui. 124:379 

 at. Soc. Ont., 39th Rep't, p. 45 

 "Wis. Nat. Hist. Soc. Bui. 7:130 (Cecidomyia 



1908 



1909 



Felt, E. P. N, 



Ct 



1909 



Burrill, A. C. 



V i t i s - 



■ p m u m) 



1910 



Stebbins, F. A. 



Springf. Mus. Nat. Hist. Bui. 2:44 



This species was first brought to notice by Messrs Walsh and 

 Riley, who characterized the gall as an apple like growth on grape- 

 vines (Vitis cordifolia). This gall is evidently widely dis- 

 tributed. It has been recorded as common in New Jersey, in the 

 vicinity of New York City, in Virginia and from Wisconsin. It is 

 comparatively easy to find a few of the characteristic galls m.ade by 

 this insect in m.ost localities in New York State and in some places 

 it is almost abundant. Num.erous large-sized galls were taken at 

 Westfield, N. Y., on the sum.m.er grape (Vitis bicolor) while 

 scattered, sm.aller specim_ens were found on the northern fox grape 

 (Vitis labrusca)at Hamburg, the larvae from both appear- 

 ing identical. 



The insect is a difficult one to rear, and it was only after repeated 

 trials that we succeeded, May 28, 1908, in obtaining an adult from 

 a niUTiber of galls collected the preceding season. The galls are 

 evidently m.odified buds and, with the advance of the season, ripen 

 and drop probably with the falling foliage. The insects rem.ain in 

 their retreats over winter and by spring the hard, woody tissues of 

 the gall seem, to have m.ostly disappeared and the flies have little 

 difficulty in em.erging from, their shelters. Larvae m.ay possibly 

 survive a second winter as living exam.ples were found in February 

 1907 in galls that were probably collected in the fall of 1906. There 

 is presumably but one generation annually. The structure of the 

 gall with its two layers of cells placed end to end and separated by 

 a thin septum, suggests that each is m.ade by a single fem.ale deposit- 

 ing her eggs in a symm.etrical manner around a young shoot. 

 Polymecus picipes Ashm. and Polygnotus sp. were 

 reared from this gall. 



Gall. The gall is sometim.es quite flattened or depressed though 

 m.ore often subspherical or flattened at the base and som.ewhat 

 pointed at the tip. The young gall is green and covered with a fine 



