254 



NEW YORK STATE MUSEUM 



Rhopalomyia fusiformis Felt 



1907 Felt, E. P. N. Y. State Mus. Bui. no, p. 120 (separate, p. 24) 



1908 N. Y. State Mus. Bui. 124, p. 364, 365, 366 



1909 



N. 



Ottawa Nat., 22: 247, 249 



The galls of this species are rather common on the narrow-leaved 

 Solidago, S. graminifolia, in midsummer, the adults appear- 

 ing the latter part of July. 



Gall. This is a peculiar ribbed, elongate structure about 6 mm 

 long, occurring singly or in masses on the stem or the under or 

 upper surface of the foliage. The color is usually very nearly that 

 of the stem or leaf though it may have a dark reddish tint. The 

 gall is slightly fusiform, it being a little enlarged above the circular 

 base and then tapering to a rather tine, frequently slightly curved 

 tip; the surface is usually strongly ribbed. Most of the galls arise 

 from the stem, and in one unusual case a cluster of eight or ten 

 galls occurred at the tip of an arrested stem. See New York State 

 Museum Bulletin 175, plate 1, figure 5, for a colored illustration. 



Larva. Length 3 mm, pale orange. 



Male. Length 2 mm. Antennae as long as the body, sparsely 

 haired, yellowish gray; 20 segments, the fifth with a stem two- 



Fig. 67 Rhopalomyia fusiformis; fifth antennal segment of male 

 and palpus, enlarged (original) 



thirds the length of the basal enlargement. Palpi composed of 

 one rather stout, elongate segment slightly enlarged at the distal 

 third. Mesonotum light brown, submedian lines yellowish, uniting 

 posteriorly in a median yellowish area. Scutcllum fuscous yellowish 

 with sparse apical setae, postscutellum yellowish brown. Abdomen 

 dark fuscous yellowish, slightly darker basally, sparsely clothed 

 with line, fuscous hairs. Genitalia very dark. Wings (Plate 

 17, figure 3), subhyaline, costa yellowish brown; halteres pale 

 yellowish basally, fuSCOUS apically. Legs nearly uniform yellowish 



fuscous, distal tarsal segments sometimes variably tinged with pale 



