REPORT OF THE STATE ENTOMOLOGIST I9T4 227 



cc Fifth antennal segment of the male with a stem as long as the basal 

 enlargement, that of the female cylindric, with a length two and one- 

 half times its diameter, the third palpal segment shorter than the 

 second; reared from an ovoid leaf gall on Salix humilis 



salicifolius Felt, C. a20i7 

 ccc Fifth antennal segment of the female sessile, with a length one-half 

 greater than its diameter, the third palpal segment three-fourths the 

 length of the second; reared from Juniperus 



b e t h e 1 i Felt, C. a2303 

 flfl 15 antennal segments 



b Abdomen dark brown, the fifth antennal segment with a stem one-third the 

 length of the basal enlargement; male; reared from Betula seeds 



b e t u 1 a e Winn., C. 964 

 aaa 16 antennal segments 



b Abdomen fuscous yellowish, the fifth antennal segment with a stem one- 

 fourth longer than the basal enlargement; reared from apical rosette gall 

 on Solidago inquilinus Felt, C. ai655a 



Oligotrophus betulae Winn. 



1886 Lintner, J. A. State Ent. 3d Rep't, p. 85-86 (Cecidomyia) 



1886 Count. Gent., 51:287 (Cecidomyia) 



1888 Inj. & Other Ins., 4th Rep't, p. 27 (parasites, Cecidomyia) 



1892 Theobald, F. V. An Account of British Flies, p. 63 



1896 Lintner, J. A. Inj. & Other Ins. N. Y., nth Rep't, p. 162-65 (Cecid- 

 omyia) 



1906 Felt, E. P. Ins. Affect. Prk. & Wdld. Trees, N. Y. State Mus. Mem. 

 8, 2: 621, 647 



1908 N. Y. State Mus. Bui. 124, p. 368 



This insect was first observed in America in 1886, when deformed 

 white birch catkins were submitted to Dr J. A. Lintner with an 

 inquiry as to the cause of the abnormal condition. It has become 

 established in Albany, the catkins of white birches in Washington 

 Park in particular being rather badly infested in some seasons. 

 This insect was so abundant in 1887 that about half of the catkins 

 were affected. It was observed at New Haven, Conn., in 1902. 

 The presence of this gall-maggot is easily detected, particularly 

 after pupation, because of the windowlike spot rendering the insect 

 visible beneath. The normal alate seed is transformed into a globose 

 gall with rudimentary alae. 



Life history. There is evidently but one generation annually, the 

 larvae becoming full grown late in the fall, wintering in the affected 

 galls, and the adults appearing in early spring. This species occurs 

 in Europe on Betula alba and a Swedish variety of B . 

 p e n d u 1 a, known as B. valecardia. European parasites 

 are Torymus pallidicornis Boh. and Leucopis 

 8 



