1012] The Ottawa Naturalist 181 



in the world than Canada. We can unhesitatingly affirm that 

 the normal waters of our lakes, streams and springs, our ground 

 waters and our deep seated sources, are of the purest. It be- 

 comes our duty as communities and individuals, to preserve 

 and protect them from pollution and to see to it that the water 

 we drink is as irreproachable in quality as that with which 

 Nature has supplied us. 



THE IDENTITY OF THE BETTER KNOWN 

 MIDGE GALLS. 



By E. P. Felt, Albany, N.Y. 



(Continued from page 167). 

 tribe oligotrophiariae. 

 The third vein in this group is well separated from the 

 anterior margin of the wing; the antennal segments are short, 

 cvlindric, usually stemmed in the male, and the claws are simple 

 or at least rudimentary. This latter character serves to differ- 

 entiate the species from the preceding tribe. The food habits, 

 like those of the Dasyneuriariae are somewhat general, though 

 there is a much greater preponderance of bud galls. 



Phytophaga Rond. 



The antennal segments in this genus range from 12 to over 

 20. the flagellate ones being stemmed in the male and usually 

 sessile in the female. The palpi are quadriarticulate. This 

 genus is distinguished from the following by the third vein 

 uniting with costa at the apex of the wing. Synonym: Maye- 

 tiola Kieff. 



P. ulmi Beutm. The larvae live among the small, immature 

 terminal leaves or inhabit leaf buds. Previously referred to 

 Cecidomyia and Mayetiola. 



P. violicola Coq. The pale yellowish larvae live in curled 

 violet leaves. Previously referred to Diplosis, Contarinia and 

 Mayetiola. 



P. destructor Sav. The yellowish larvae injure the stems 

 of wheat and other grains under the leaf sheath. Widely known 

 as the Hessian fly. Previously referred to Cecidomyia and 

 Mayetiola. 



P. rigidae O.S. Gall an apical or subapical enlargement on 

 willow stems, fusiform in shape, about an inch long and tipped 

 with a rather characteristic slender, curved beak. Previously 

 referred to Cecidomyia and Rhabdophaga. 



