354 THE CANADIAN ENTOMOLOGIST 



contains a single row of 5-20 larval chambers. Length from about 

 25 to 50 mm. Width 3-5 mm. 



Habitat — Toronto, Canada (A. Cosens). 



The gall of this species has long been known. Saunders 

 mentions it in his "Insects Injurious to Fruits," 1887, p. 331, and 

 calls it the Strawberry Leaf-Stem Gall. Prof. S. A. Forbes also 

 mentions the gall in the 22nd Report of the State Entomologist of 

 Illinois, 1883 (1884), p. 97. H. F. Bassett speaks of a Cynipidous 

 gall occasionally seen on the petiole of strawberry leaves (Trans. 

 Am. Ent. Soc, Vol. XXVI, 1900, p. 325). Mr. L. H. Weld found 

 the galls at Ithaca, New York and Evanston, Illinois and I found 

 the same in the vicinity of New York City for some years past. 

 In August, 1913, Mr. A. Cosens collected the gall on wild straw- 

 berry in Toronto, Canada. He transplanted some of the infested 

 plants into pots and managed to mature the galls from which 

 he reared five males, being the first one to succeed in obtaining 

 the flies. 



The illustration is from a sketch made by Mr. Weld and re- 

 drawn by Mrs. E. L. Beutenmuller. 



NOTES ON THE STRAWBERRY LEAF PETIOLE GALL 

 (DIASTROPHUS FRAGARIJE BEUTM.) 



r 



BY A. COSENS, PH.D., TORONTO, ONT. 



A cylindrical enlargement of the leaf petiole of Fragaria 

 virginiana Duch . constitutes the gall . 1 1 has a somewhat segmented 

 appearance owing to the separation of each larval cell from 

 the adjoining one by a shallow annular constriction. The sur- 

 face is usually coloured a rich reddish brown and bears a 

 pubescence, varying with that of the petiole from which the 

 gall originates. The species from which the producers were ob- 

 tained was glabrous. 



Length 10-50 mm. Diam. 3 mm. 



In comparison with Diastrophiis fusiformans Ashmead 

 on Potentilla monspeliensis var. norvegica (L) Rydb. this species 

 differs in the following particulars: The arrangement of its 



November, 1915. 



