REPORT OF THE STATE ENTOMOLOGIST 1918 



227 



Trishormomyia helianthi Brodie 



1894 Brodie, William. Biol. Rev. of Ont,, 1:44-46 (Cecidomyia) 



1909 Jarvis, T. D. Ent. Soc. Ont., 39th Rep't, p. 83 (Cecidomyia) 



1913 Felt, E. P. Can. Ent., 40:418 (Hormomyia) 



191 8 N. Y. State Mus. Bui. 200, p. 206, 207 (Hormomyia) 



This species produces on Helianthus more or less cylindrical 

 flask-shaped galls (fig. 49, pi. 11, fig. 2) having a length of 10 to 25 

 mm and a diameter of from 1.5 to 5 mm. There may be one to ten 

 galls in an axile, firmly attached to the stem by an expanded base 

 and projecting in various directions, usually upwards, often at right 



Fig. 49 Trishormomyia helianthi, 

 tubular galls on Helianthus (author's 

 illustration) 



angles to the stem, and occasionally downward. They occur on the 

 upper third of the stems ofH. decapetalus and H. d i v a r i - 

 c a t u s. They are also found onH. annuus. The gall has been 

 collected about Toronto, Canada, Evanston, 111., and Salt Lake City, 

 Utah. It is local at Evanston, III, occurring in September (L. H. 

 Weld). 



Trishormomyia bulla Felt 

 1867 Walsh, B. D. Ent. Soc. Phila. Proc, 6:226 (Cecidomyia) 

 1894 Brodie, William. Biol. Rev. of Ont., i :74 (Cecidomyia) 

 1909 Jarvis, T. D. Ent. Soc. Ont., 39th Rep't, p. 83 (Cecidomyia) 

 1912 Cosens, A. Can. Inst. Trans., 9:317 (Cecidomyia) 

 1914 Felt, E. P. Can. Ent., 46:286-87 (Hormomyia) 

 191 8 N. Y. State Mus. Bui. 200, p. 206 (Hormomyia) 



This species produces subglobular yellowish galls (pi. 11, fig- i) 

 about the size of large peas on Helianthus leaves, the deformities 

 being about equally prominent on both surfaces and irregularly 

 located, however, usually near the midrib. The gall has been 

 recorded from Ontario, Canada, and Evanston, 111. It occurs com- 

 monly in July on plants in a deep rich soil at North Evanston, 111. 

 IS 



